/*
 Low Level Linux Driver for the IBM Microchannel SCSI Subsystem for
 Linux Kernel >= 2.4.0.
 Copyright (c) 1995 Strom Systems, Inc. under the terms of the GNU
 General Public License. Written by Martin Kolinek, December 1995.
 Further development by: Chris Beauregard, Klaus Kudielka, Michael Lang
 See the file README.ibmmca for a detailed description of this driver,
 the commandline arguments and the history of its development.
 See the WWW-page: http://www.uni-mainz.de/~langm000/linux.html for latest
 updates, info and ADF-files for adapters supported by this driver.
*/

#ifndef LINUX_VERSION_CODE
#include <linux/version.h>
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,0)
#error "This driver works only with kernel 2.4.0 or higher!"
#endif
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/blk.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/mca.h>
#include <asm/system.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <linux/init.h>
#include "sd.h"
#include "scsi.h"
#include "hosts.h"
#include "ibmmca.h"
#include <linux/config.h>

/* current version of this driver-source: */
#define IBMMCA_SCSI_DRIVER_VERSION "4.0a"

#define IBMLOCK spin_lock_irqsave(&io_request_lock, flags);
#define IBMUNLOCK spin_unlock_irqrestore(&io_request_lock, flags);

/* driver configuration */
#define IM_MAX_HOSTS     8 /* maximum number of host adapters */
#define IM_RESET_DELAY	60 /* seconds allowed for a reset */

/* driver debugging - #undef all for normal operation */
/* if defined: count interrupts and ignore this special one: */
#undef	IM_DEBUG_TIMEOUT	50            
#define TIMEOUT_PUN	0
#define TIMEOUT_LUN	0
/* verbose interrupt: */
#undef IM_DEBUG_INT                   
/* verbose queuecommand: */
#undef IM_DEBUG_CMD    
/* verbose queucommand for specific SCSI-device type: */
#undef IM_DEBUG_CMD_SPEC_DEV
/* verbose device probing */
#undef IM_DEBUG_PROBE

/* device type that shall be displayed on syslog (only during debugging): */
#define IM_DEBUG_CMD_DEVICE	TYPE_TAPE

/* relative addresses of hardware registers on a subsystem */
#define IM_CMD_REG(hi)	(hosts[(hi)]->io_port)   /*Command Interface, (4 bytes long) */
#define IM_ATTN_REG(hi)	(hosts[(hi)]->io_port+4) /*Attention (1 byte) */
#define IM_CTR_REG(hi)	(hosts[(hi)]->io_port+5) /*Basic Control (1 byte) */
#define IM_INTR_REG(hi)	(hosts[(hi)]->io_port+6) /*Interrupt Status (1 byte, r/o) */
#define IM_STAT_REG(hi)	(hosts[(hi)]->io_port+7) /*Basic Status (1 byte, read only) */

/* basic I/O-port of first adapter */
#define IM_IO_PORT	0x3540
/* maximum number of hosts that can be found */
#define IM_N_IO_PORT	8

/*requests going into the upper nibble of the Attention register */
/*note: the lower nibble specifies the device(0-14), or subsystem(15) */
#define IM_IMM_CMD	0x10	/*immediate command */
#define IM_SCB		0x30	/*Subsystem Control Block command */
#define IM_LONG_SCB	0x40	/*long Subsystem Control Block command */
#define IM_EOI		0xe0	/*end-of-interrupt request */

/*values for bits 7,1,0 of Basic Control reg. (bits 6-2 reserved) */
#define IM_HW_RESET	0x80	/*hardware reset */
#define IM_ENABLE_DMA	0x02	/*enable subsystem's busmaster DMA */
#define IM_ENABLE_INTR	0x01	/*enable interrupts to the system */

/*to interpret the upper nibble of Interrupt Status register */
/*note: the lower nibble specifies the device(0-14), or subsystem(15) */
#define IM_SCB_CMD_COMPLETED			0x10
#define IM_SCB_CMD_COMPLETED_WITH_RETRIES	0x50
#define IM_LOOP_SCATTER_BUFFER_FULL		0x60
#define IM_ADAPTER_HW_FAILURE			0x70
#define IM_IMMEDIATE_CMD_COMPLETED		0xa0
#define IM_CMD_COMPLETED_WITH_FAILURE		0xc0
#define IM_CMD_ERROR				0xe0
#define IM_SOFTWARE_SEQUENCING_ERROR		0xf0

/*to interpret bits 3-0 of Basic Status register (bits 7-4 reserved) */
#define IM_CMD_REG_FULL		0x08
#define IM_CMD_REG_EMPTY	0x04
#define IM_INTR_REQUEST		0x02
#define IM_BUSY			0x01

/*immediate commands (word written into low 2 bytes of command reg) */
#define IM_RESET_IMM_CMD	0x0400
#define IM_FEATURE_CTR_IMM_CMD	0x040c
#define IM_DMA_PACING_IMM_CMD	0x040d
#define IM_ASSIGN_IMM_CMD	0x040e
#define IM_ABORT_IMM_CMD	0x040f
#define IM_FORMAT_PREP_IMM_CMD	0x0417

/*SCB (Subsystem Control Block) structure */
struct im_scb {
   unsigned short command; /*command word (read, etc.) */
   unsigned short enable; /*enable word, modifies cmd */
   union {
      unsigned long log_blk_adr; /*block address on SCSI device */
      unsigned char scsi_cmd_length; /*6,10,12, for other scsi cmd */
   } u1;
   unsigned long sys_buf_adr; /*physical system memory adr */
   unsigned long sys_buf_length; /*size of sys mem buffer */
   unsigned long tsb_adr; /*Termination Status Block adr */
   unsigned long scb_chain_adr;	/*optional SCB chain address */
   union {
      struct {
	 unsigned short count; /*block count, on SCSI device */
	 unsigned short length;	/*block length, on SCSI device */
      } blk;
      unsigned char scsi_command[12]; /*other scsi command */
   } u2;
};

/*structure scatter-gather element (for list of system memory areas) */
struct im_sge {
   void *address;
   unsigned long byte_length;
};

/*structure returned by a get_pos_info command: */
struct im_pos_info {
   unsigned short pos_id;         /* adapter id */
   unsigned char pos_3a;          /* pos 3 (if pos 6 = 0) */
   unsigned char pos_2;           /* pos 2 */
   unsigned char int_level;       /* interrupt level IRQ 11 or 14 */
   unsigned char pos_4a;          /* pos 4 (if pos 6 = 0) */
   unsigned short connector_size; /* MCA connector size: 16 or 32 Bit */
   unsigned char num_luns;        /* number of supported luns per device */
   unsigned char num_puns;        /* number of supported puns */
   unsigned char pacing_factor;   /* pacing factor */
   unsigned char num_ldns;        /* number of ldns available */
   unsigned char eoi_off;         /* time EOI and interrupt inactive */
   unsigned char max_busy;        /* time between reset and busy on */
   unsigned short cache_stat;     /* ldn cachestat. Bit=1 = not cached */
   unsigned short retry_stat;     /* retry status of ldns. Bit=1=disabled */
   unsigned char pos_4b;          /* pos 4 (if pos 6 = 1) */
   unsigned char pos_3b;          /* pos 3 (if pos 6 = 1) */
   unsigned char pos_6;           /* pos 6 */
   unsigned char pos_5;           /* pos 5 */ 
   unsigned short max_overlap;    /* maximum overlapping requests */
   unsigned short num_bus;        /* number of SCSI-busses */
};

/*values for SCB command word */
#define IM_NO_SYNCHRONOUS      0x0040	/*flag for any command */
#define IM_NO_DISCONNECT       0x0080	/*flag for any command */
#define IM_READ_DATA_CMD       0x1c01
#define IM_WRITE_DATA_CMD      0x1c02
#define IM_READ_VERIFY_CMD     0x1c03
#define IM_WRITE_VERIFY_CMD    0x1c04
#define IM_REQUEST_SENSE_CMD   0x1c08
#define IM_READ_CAPACITY_CMD   0x1c09
#define IM_DEVICE_INQUIRY_CMD  0x1c0b
#define IM_READ_LOGICAL_CMD    0x1c2a
#define IM_OTHER_SCSI_CMD_CMD  0x241f

/* unused, but supported, SCB commands */
#define IM_GET_COMMAND_COMPLETE_STATUS_CMD   0x1c07 /* command status */
#define IM_GET_POS_INFO_CMD                  0x1c0a /* returns neat stuff */
#define IM_READ_PREFETCH_CMD                 0x1c31 /* caching controller only */
#define IM_FOMAT_UNIT_CMD                    0x1c16 /* format unit */
#define IM_REASSIGN_BLOCK_CMD                0x1c18 /* in case of error */

/*values to set bits in the enable word of SCB */
#define IM_READ_CONTROL              0x8000
#define IM_REPORT_TSB_ONLY_ON_ERROR  0x4000
#define IM_RETRY_ENABLE              0x2000
#define IM_POINTER_TO_LIST           0x1000
#define IM_SUPRESS_EXCEPTION_SHORT   0x0400
#define IM_BYPASS_BUFFER             0x0200
#define IM_CHAIN_ON_NO_ERROR         0x0001

/*TSB (Termination Status Block) structure */
struct im_tsb {
   unsigned short end_status;
   unsigned short reserved1;
   unsigned long residual_byte_count;
   unsigned long sg_list_element_adr;
   unsigned short status_length;
   unsigned char dev_status;
   unsigned char cmd_status;
   unsigned char dev_error;
   unsigned char cmd_error;
   unsigned short reserved2;
   unsigned short reserved3;
   unsigned short low_of_last_scb_adr;
   unsigned short high_of_last_scb_adr;
};

/*subsystem uses interrupt request level 14 */
#define IM_IRQ     14
/*SCSI-2 F/W may evade to interrupt 11 */
#define IM_IRQ_FW  11

/* Model 95 has an additional alphanumeric display, which can be used
   to display SCSI-activities. 8595 models do not have any disk led, which
   makes this feature quite useful.
   The regular PS/2 disk led is turned on/off by bits 6,7 of system
   control port. */

/* LED display-port (actually, last LED on display) */
#define MOD95_LED_PORT	   0x108
/* system-control-register of PS/2s with diskindicator */
#define PS2_SYS_CTR        0x92
/* activity displaying methods */
#define LED_DISP           1
#define LED_ADISP          2
#define LED_ACTIVITY       4
/* failed intr */
#define CMD_FAIL           255

/* The SCSI-ID(!) of the accessed SCSI-device is shown on PS/2-95 machines' LED
   displays. ldn is no longer displayed here, because the ldn mapping is now 
   done dynamically and the ldn <-> pun,lun maps can be looked-up at boottime 
   or during uptime in /proc/scsi/ibmmca/<host_no> in case of trouble, 
   interest, debugging or just for having fun. The left number gives the
   host-adapter number and the right shows the accessed SCSI-ID. */

/* display_mode is set by the ibmmcascsi= command line arg */
static int display_mode = 0;
/* set default adapter timeout */
static unsigned int adapter_timeout = 45;
/* for probing on feature-command: */
static unsigned int global_command_error_excuse = 0;
/* global setting by command line for adapter_speed */
static int global_adapter_speed = 0; /* full speed by default */

/* Panel / LED on, do it right for F/W addressin, too. adisplay will
 * just ignore ids>7, as the panel has only 7 digits available */
#define PS2_DISK_LED_ON(ad,id) { if (display_mode & LED_DISP) { if (id>9) \
    outw((ad+48)|((id+55)<<8), MOD95_LED_PORT ); else \
    outw((ad+48)|((id+48)<<8), MOD95_LED_PORT ); } else \
    if (display_mode & LED_ADISP) { if (id<7) outb((char)(id+48),MOD95_LED_PORT+1+id); \
    outb((char)(ad+48), MOD95_LED_PORT); } \
    if ((display_mode & LED_ACTIVITY)||(!display_mode)) \
    outb(inb(PS2_SYS_CTR) | 0xc0, PS2_SYS_CTR); }

/* Panel / LED off */
/* bug fixed, Dec 15, 1997, where | was replaced by & here */
#define PS2_DISK_LED_OFF() { if (display_mode & LED_DISP) \
    outw(0x2020, MOD95_LED_PORT ); else if (display_mode & LED_ADISP) { \
    outl(0x20202020,MOD95_LED_PORT); outl(0x20202020,MOD95_LED_PORT+4); } \
    if ((display_mode & LED_ACTIVITY)||(!display_mode)) \
    outb(inb(PS2_SYS_CTR) & 0x3f, PS2_SYS_CTR); }

/*list of supported subsystems */
struct subsys_list_struct {
   unsigned short mca_id;
   char *description;
};

/* types of different supported hardware that goes to hostdata special */
#define IBM_SCSI2_FW     0
#define IBM_7568_WCACHE  1
#define IBM_EXP_UNIT     2
#define IBM_SCSI_WCACHE  3
#define IBM_SCSI         4

/* other special flags for hostdata structure */
#define FORCED_DETECTION         100
#define INTEGRATED_SCSI          101

/* List of possible IBM-SCSI-adapters */
struct subsys_list_struct subsys_list[] = {
 {0x8efc,"IBM SCSI-2 F/W Adapter"}, /* special = 0 */
 {0x8efd,"IBM 7568 Industrial Computer SCSI Adapter w/Cache"}, /* special = 1 */
 {0x8ef8,"IBM Expansion Unit SCSI Controller"},/* special = 2 */
 {0x8eff,"IBM SCSI Adapter w/Cache"}, /* special = 3 */
 {0x8efe,"IBM SCSI Adapter"}, /* special = 4 */
};

/* Max number of logical devices (can be up from 0 to 14).  15 is the address
of the adapter itself. */
#define MAX_LOG_DEV  15

/*local data for a logical device */
struct logical_device {
   struct im_scb scb; /* SCSI-subsystem-control-block structure */
   struct im_tsb tsb; /* SCSI command complete status block structure */
   struct im_sge sge[16]; /* scatter gather list structure */
   unsigned char buf[256]; /* SCSI command return data buffer */
   Scsi_Cmnd *cmd;  /* SCSI-command that is currently in progress */
   int device_type; /* type of the SCSI-device. See include/scsi/scsi.h
		       for interpretation of the possible values */
   int block_length; /* blocksize of a particular logical SCSI-device */
   int cache_flag; /* 1 if this is uncached, 0 if cache is present for ldn */
   int retry_flag; /* 1 if adapter retry is disabled, 0 if enabled */
};

/* statistics of the driver during operations (for proc_info) */
struct Driver_Statistics {
   /* SCSI statistics on the adapter */
   int ldn_access[MAX_LOG_DEV+1];         /* total accesses on a ldn */
   int ldn_read_access[MAX_LOG_DEV+1];    /* total read-access on a ldn */
   int ldn_write_access[MAX_LOG_DEV+1];   /* total write-access on a ldn */
   int ldn_inquiry_access[MAX_LOG_DEV+1]; /* total inquiries on a ldn */
   int ldn_modeselect_access[MAX_LOG_DEV+1]; /* total mode selects on ldn */
   int scbs;                              /* short SCBs queued */
   int long_scbs;                         /* long SCBs queued */
   int total_accesses;                    /* total accesses on all ldns */
   int total_interrupts;                  /* total interrupts (should be
					     same as total_accesses) */
   int total_errors;                      /* command completed with error */
   /* dynamical assignment statistics */
   int total_scsi_devices;                /* number of physical pun,lun */
   int dyn_flag;                          /* flag showing dynamical mode */
   int dynamical_assignments;             /* number of remappings of ldns */
   int ldn_assignments[MAX_LOG_DEV+1];    /* number of remappings of each
					     ldn */
};

/* data structure for each host adapter */
struct ibmmca_hostdata {
   /* array of logical devices: */
   struct logical_device _ld[MAX_LOG_DEV+1];   
   /* array to convert (pun, lun) into logical device number: */
   unsigned char _get_ldn[16][8];
   /*array that contains the information about the physical SCSI-devices
    attached to this host adapter: */
   unsigned char _get_scsi[16][8];
   /* used only when checking logical devices: */
   int _local_checking_phase_flag;
   /* report received interrupt: */
   int _got_interrupt;
   /* report termination-status of SCSI-command: */
   int _stat_result;
   /* reset status (used only when doing reset): */
   int _reset_status;
   /* code of the last SCSI command (needed for panic info): */
   int _last_scsi_command[MAX_LOG_DEV+1];
   /* identifier of the last SCSI-command type */
   int _last_scsi_type[MAX_LOG_DEV+1];
   /* last blockcount */
   int _last_scsi_blockcount[MAX_LOG_DEV+1];
   /* last locgical block address */
   unsigned long _last_scsi_logical_block[MAX_LOG_DEV+1];
   /* Counter that points on the next reassignable ldn for dynamical
      remapping. The default value is 7, that is the first reassignable
      number in the list at boottime: */
   int _next_ldn;
   /* Statistics-structure for this IBM-SCSI-host: */
   struct Driver_Statistics _IBM_DS;
   /* This hostadapters pos-registers pos2 until pos6 */
   unsigned int _pos[8];
   /* assign a special variable, that contains dedicated info about the
    adaptertype */
   int _special;
   /* connector size on the MCA bus */
   int _connector_size;
   /* synchronous SCSI transfer rate bitpattern */
   int _adapter_speed;
};

/* macros to access host data structure */
#define subsystem_pun(hi) (hosts[(hi)]->this_id)
#define subsystem_maxid(hi) (hosts[(hi)]->max_id)
#define ld(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_ld)
#define get_ldn(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_get_ldn)
#define get_scsi(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_get_scsi)
#define local_checking_phase_flag(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_local_checking_phase_flag)
#define got_interrupt(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_got_interrupt)
#define stat_result(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_stat_result)
#define reset_status(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_reset_status)
#define last_scsi_command(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_last_scsi_command)
#define last_scsi_type(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_last_scsi_type)
#define last_scsi_blockcount(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_last_scsi_blockcount)
#define last_scsi_logical_block(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_last_scsi_logical_block)
#define last_scsi_type(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_last_scsi_type)
#define next_ldn(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_next_ldn)
#define IBM_DS(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_IBM_DS)
#define special(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_special)
#define subsystem_connector_size(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_connector_size)
#define adapter_speed(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_adapter_speed)
#define pos2(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_pos[2])
#define pos3(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_pos[3])
#define pos4(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_pos[4])
#define pos5(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_pos[5])
#define pos6(hi) (((struct ibmmca_hostdata *) hosts[(hi)]->hostdata)->_pos[6])

/* Define a arbitrary number as subsystem-marker-type. This number is, as
   described in the ANSI-SCSI-standard, not occupied by other device-types. */
#define TYPE_IBM_SCSI_ADAPTER   0x2F

/* Define 0xFF for no device type, because this type is not defined within
   the ANSI-SCSI-standard, therefore, it can be used and should not cause any
   harm. */
#define TYPE_NO_DEVICE          0xFF

/* define medium-changer. If this is not defined previously, e.g. Linux
   2.0.x, define this type here. */
#ifndef TYPE_MEDIUM_CHANGER
#define TYPE_MEDIUM_CHANGER     0x08
#endif

/* define possible operations for the immediate_assign command */
#define SET_LDN        0
#define REMOVE_LDN     1

/* ldn which is used to probe the SCSI devices */
#define PROBE_LDN      0

/* reset status flag contents */
#define IM_RESET_NOT_IN_PROGRESS         0
#define IM_RESET_IN_PROGRESS             1
#define IM_RESET_FINISHED_OK             2
#define IM_RESET_FINISHED_FAIL           3
#define IM_RESET_NOT_IN_PROGRESS_NO_INT  4
#define IM_RESET_FINISHED_OK_NO_INT      5

/* define undefined SCSI-command */
#define NO_SCSI                  0xffff

/*-----------------------------------------------------------------------*/

/* if this is nonzero, ibmmcascsi option has been passed to the kernel */
static int io_port[IM_MAX_HOSTS] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static int scsi_id[IM_MAX_HOSTS] = { 7, 7, 7, 7, 7, 7, 7, 7 };

/* fill module-parameters only, when this define is present.
   (that is kernel version 2.1.x) */
#if defined(MODULE)
static char *boot_options = NULL;
#include <linux/module.h>
MODULE_PARM(boot_options, "s");
MODULE_PARM(io_port, "1-" __MODULE_STRING(IM_MAX_HOSTS) "i");
MODULE_PARM(scsi_id, "1-" __MODULE_STRING(IM_MAX_HOSTS) "i");
MODULE_PARM(display, "1i");
MODULE_PARM(adisplay, "1i");
MODULE_PARM(normal, "1i");
MODULE_PARM(ansi, "1i");
#endif
/*counter of concurrent disk read/writes, to turn on/off disk led */
static int disk_rw_in_progress = 0;

/* host information */
static int found = 0;
static struct Scsi_Host *hosts[IM_MAX_HOSTS+1] = {
   NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL };
static unsigned int pos[8]; /* whole pos register-line for diagnosis */
/* Taking into account the additions, made by ZP Gu.
 * This selects now the preset value from the configfile and
 * offers the 'normal' commandline option to be accepted */
#ifdef CONFIG_IBMMCA_SCSI_ORDER_STANDARD
static char ibm_ansi_order = 1;
#else
static char ibm_ansi_order = 0;
#endif

static void interrupt_handler (int, void *, struct pt_regs *);
static void issue_cmd (int, unsigned long, unsigned char);
static void internal_done (Scsi_Cmnd * cmd);
static void check_devices (int, int);
static int immediate_assign(int, unsigned int, unsigned int, unsigned int,
                            unsigned int);
static int immediate_feature(int, unsigned int, unsigned int);
#ifdef CONFIG_IBMMCA_SCSI_DEV_RESET
static int immediate_reset(int, unsigned int);
#endif
static int device_inquiry(int, int);
static int read_capacity(int, int);
static int get_pos_info(int);
static char *ti_p(int);
static char *ti_l(int);
static char *ibmrate(unsigned int, int);
static int probe_display(int);
static int probe_bus_mode(int);
static int device_exists (int, int, int *, int *);
static struct Scsi_Host *ibmmca_register(Scsi_Host_Template *,
					 int, int, int, char *);
static int option_setup(char *);
/* local functions needed for proc_info */
static int ldn_access_load(int, int);
static int ldn_access_total_read_write(int);

static void interrupt_handler (int irq, void *dev_id, struct pt_regs *regs)
{
   int host_index, ihost_index;
   unsigned int intr_reg;
   unsigned int cmd_result;
   unsigned int ldn;
   unsigned long flags;
   Scsi_Cmnd *cmd;
   int lastSCSI;

   IBMLOCK
   /* search for one adapter-response on shared interrupt */
   for (host_index=0;
	hosts[host_index] && !(inb(IM_STAT_REG(host_index)) & IM_INTR_REQUEST);
	host_index++);
   /* return if some other device on this IRQ caused the interrupt */
   if (!hosts[host_index]) {
      IBMUNLOCK
      return;
   }

   /* the reset-function already did all the job, even ints got
      renabled on the subsystem, so just return */
   if ((reset_status(host_index) == IM_RESET_NOT_IN_PROGRESS_NO_INT)||
       (reset_status(host_index) == IM_RESET_FINISHED_OK_NO_INT)) {
      reset_status(host_index) = IM_RESET_NOT_IN_PROGRESS;
      IBMUNLOCK
      return;
   }

   /*must wait for attention reg not busy, then send EOI to subsystem */
   while (1) {
      if (!(inb (IM_STAT_REG(host_index)) & IM_BUSY)) break;
      IBMUNLOCK /* cycle interrupt */
      IBMLOCK
   }
   ihost_index=host_index;
   /*get command result and logical device */
   intr_reg = (unsigned char)(inb (IM_INTR_REG(ihost_index)));
   cmd_result = intr_reg & 0xf0;
   ldn = intr_reg & 0x0f;
   /* get the last_scsi_command here */
   lastSCSI = last_scsi_command(ihost_index)[ldn];
   outb (IM_EOI | ldn, IM_ATTN_REG(ihost_index));
   IBMUNLOCK
   /*these should never happen (hw fails, or a local programming bug) */
   if (!global_command_error_excuse) {
      switch (cmd_result) {
	 /* Prevent from Ooopsing on error to show the real reason */
       case IM_ADAPTER_HW_FAILURE:
       case IM_SOFTWARE_SEQUENCING_ERROR:
       case IM_CMD_ERROR:
	 printk("\nIBM MCA SCSI: Fatal Subsystem ERROR!\n");
	 printk("              Last cmd=0x%x, ena=%x, len=",lastSCSI,
		ld(ihost_index)[ldn].scb.enable);
	 if (ld(ihost_index)[ldn].cmd)
	   printk("%ld/%ld,",(long)(ld(ihost_index)[ldn].cmd->request_bufflen),
		  (long)(ld(ihost_index)[ldn].scb.sys_buf_length));
	 else
	   printk("none,");
	 if (ld(ihost_index)[ldn].cmd)
	   printk("Blocksize=%d",ld(ihost_index)[ldn].scb.u2.blk.length);
	 else
	   printk("Blocksize=none");
	 printk(", host=0x%x, ldn=0x%x\n",ihost_index, ldn);
	 if (ld(ihost_index)[ldn].cmd) {
	    printk("Blockcount=%d/%d\n",last_scsi_blockcount(ihost_index)[ldn],
		   ld(ihost_index)[ldn].scb.u2.blk.count);
	    printk("Logical block=%lx/%lx\n",last_scsi_logical_block(ihost_index)[ldn],
		   ld(ihost_index)[ldn].scb.u1.log_blk_adr);
	 }
	 printk("Reason given: %s\n",
		(cmd_result==IM_ADAPTER_HW_FAILURE) ? "HARDWARE FAILURE" :
		(cmd_result==IM_SOFTWARE_SEQUENCING_ERROR) ? "SOFTWARE SEQUENCING ERROR" :
		(cmd_result==IM_CMD_ERROR) ? "COMMAND ERROR" : "UNKNOWN");
	 /* if errors appear, enter this section to give detailed info */
	 printk("IBM MCA SCSI: Subsystem Error-Status follows:\n");
	 printk("              Command Type................: %x\n",
		last_scsi_type(ihost_index)[ldn]);
	 printk("              Attention Register..........: %x\n",
		inb (IM_ATTN_REG(ihost_index)));
	 printk("              Basic Control Register......: %x\n",
		inb (IM_CTR_REG(ihost_index)));
	 printk("              Interrupt Status Register...: %x\n",
		intr_reg);
	 printk("              Basic Status Register.......: %x\n",
		inb (IM_STAT_REG(ihost_index)));
	 if ((last_scsi_type(ihost_index)[ldn]==IM_SCB)||
	     (last_scsi_type(ihost_index)[ldn]==IM_LONG_SCB)) {
	    printk("              SCB-Command.................: %x\n",
		   ld(ihost_index)[ldn].scb.command);
	    printk("              SCB-Enable..................: %x\n",
		   ld(ihost_index)[ldn].scb.enable);
	    printk("              SCB-logical block address...: %lx\n",
		   ld(ihost_index)[ldn].scb.u1.log_blk_adr);
	    printk("              SCB-system buffer address...: %lx\n",
		   ld(ihost_index)[ldn].scb.sys_buf_adr);
	    printk("              SCB-system buffer length....: %lx\n",
		   ld(ihost_index)[ldn].scb.sys_buf_length);
	    printk("              SCB-tsb address.............: %lx\n",
		   ld(ihost_index)[ldn].scb.tsb_adr);
	    printk("              SCB-Chain address...........: %lx\n",
		   ld(ihost_index)[ldn].scb.scb_chain_adr);
	    printk("              SCB-block count.............: %x\n",
		   ld(ihost_index)[ldn].scb.u2.blk.count);
	    printk("              SCB-block length............: %x\n",
		   ld(ihost_index)[ldn].scb.u2.blk.length);
	 }
	 printk("              Send this report to the maintainer.\n");
	 panic("IBM MCA SCSI: Fatal errormessage from the subsystem (0x%X,0x%X)!\n",
	       lastSCSI,cmd_result);
	 break;
      }
   } else {
      /* The command error handling is made silent, but we tell the
       * calling function, that there is a reported error from the
       * adapter. */
      switch (cmd_result) {
       case IM_ADAPTER_HW_FAILURE: case IM_SOFTWARE_SEQUENCING_ERROR:
       case IM_CMD_ERROR: global_command_error_excuse = CMD_FAIL; break;
       default: global_command_error_excuse = 0; break;
      }
   }
   /* if no panic appeared, increase the interrupt-counter */
   IBM_DS(ihost_index).total_interrupts++;
   /*only for local checking phase */
   if (local_checking_phase_flag(ihost_index)) {
      stat_result(ihost_index) = cmd_result;
      got_interrupt(ihost_index) = 1;
      reset_status(ihost_index) = IM_RESET_FINISHED_OK;
      last_scsi_command(ihost_index)[ldn] = NO_SCSI;
      return;
   }
   /* handling of commands coming from upper level of scsi driver */
   if (last_scsi_type(ihost_index)[ldn] == IM_IMM_CMD) {
      /* verify ldn, and may handle rare reset immediate command */
      if ((reset_status(ihost_index) == IM_RESET_IN_PROGRESS)&&
	  (last_scsi_command(ihost_index)[ldn] == IM_RESET_IMM_CMD)) {
	 if (cmd_result == IM_CMD_COMPLETED_WITH_FAILURE) {
	    disk_rw_in_progress = 0;
	    PS2_DISK_LED_OFF ();
	    reset_status(ihost_index) = IM_RESET_FINISHED_FAIL;
	 } else {
	    /*reset disk led counter, turn off disk led */
	    disk_rw_in_progress = 0;
	    PS2_DISK_LED_OFF ();
	    reset_status(ihost_index) = IM_RESET_FINISHED_OK;
	 }
	 stat_result(ihost_index) = cmd_result;
	 last_scsi_command(ihost_index)[ldn] = NO_SCSI;
	 last_scsi_type(ihost_index)[ldn] = 0;
	 return;
      } else if (last_scsi_command(ihost_index)[ldn] == IM_ABORT_IMM_CMD) {
	 /* react on SCSI abort command */
#ifdef IM_DEBUG_PROBE
	 printk("IBM MCA SCSI: Interrupt from SCSI-abort.\n");
#endif
	 disk_rw_in_progress = 0;
	 PS2_DISK_LED_OFF();
	 cmd = ld(ihost_index)[ldn].cmd;
	 ld(ihost_index)[ldn].cmd = NULL;
	 if (cmd_result == IM_CMD_COMPLETED_WITH_FAILURE)
	   cmd->result = DID_NO_CONNECT << 16;
	 else
	   cmd->result = DID_ABORT << 16;
	 stat_result(ihost_index) = cmd_result;
	 last_scsi_command(ihost_index)[ldn] = NO_SCSI;
	 last_scsi_type(ihost_index)[ldn] = 0;
	 if (cmd->scsi_done)
	   (cmd->scsi_done)(cmd); /* should be the internal_done */
	 return;
      } else {
	 disk_rw_in_progress = 0;
	 PS2_DISK_LED_OFF ();
	 reset_status(ihost_index) = IM_RESET_FINISHED_OK;
	 stat_result(ihost_index) = cmd_result;
	 last_scsi_command(ihost_index)[ldn] = NO_SCSI;
	 return;
      }
   }
   last_scsi_command(ihost_index)[ldn] = NO_SCSI;
   last_scsi_type(ihost_index)[ldn] = 0;
   cmd = ld(ihost_index)[ldn].cmd;
   ld(ihost_index)[ldn].cmd = NULL;
#ifdef IM_DEBUG_TIMEOUT
   if (cmd) {
      if ((cmd->target == TIMEOUT_PUN)&&(cmd->lun == TIMEOUT_LUN)) {
	 printk("IBM MCA SCSI: Ignoring interrupt from pun=%x, lun=%x.\n",
		cmd->target, cmd->lun);
	 return;
      }
   }
#endif
   /*if no command structure, just return, else clear cmd */
   if (!cmd) return;

#ifdef IM_DEBUG_INT
   printk("cmd=%02x ireg=%02x ds=%02x cs=%02x de=%02x ce=%02x\n",
	  cmd->cmnd[0], intr_reg,
	  ld(ihost_index)[ldn].tsb.dev_status,
	  ld(ihost_index)[ldn].tsb.cmd_status,
	  ld(ihost_index)[ldn].tsb.dev_error,
	  ld(ihost_index)[ldn].tsb.cmd_error);
#endif
   /*if this is end of media read/write, may turn off PS/2 disk led */
   if ((ld(ihost_index)[ldn].device_type!=TYPE_NO_LUN)&&
       (ld(ihost_index)[ldn].device_type!=TYPE_NO_DEVICE)) {
      /* only access this, if there was a valid device addressed */
      if (--disk_rw_in_progress == 0) PS2_DISK_LED_OFF ();
   }

   /* IBM describes the status-mask to be 0x1e, but this is not conform
    * with SCSI-definition, I suppose, the reason for it is that IBM
    * adapters do not support CMD_TERMINATED, TASK_SET_FULL and
    * ACA_ACTIVE as returning statusbyte information. (ML) */
   if (cmd_result == IM_CMD_COMPLETED_WITH_FAILURE) {
      cmd->result = (unsigned char)(ld(ihost_index)[ldn].tsb.dev_status & 0x1e);
      IBM_DS(ihost_index).total_errors++;
   } else
     cmd->result = 0;
   /* write device status into cmd->result, and call done function */
   if (lastSCSI == NO_SCSI) { /* unexpected interrupt :-( */
      cmd->result |= DID_BAD_INTR << 16;
      printk("IBM MCA SCSI: WARNING - Interrupt from non-pending SCSI-command!\n");
   } else /* things went right :-) */
     cmd->result |= DID_OK << 16;
   if (cmd->scsi_done) (cmd->scsi_done)(cmd);
   return;
}

static void issue_cmd (int host_index, unsigned long cmd_reg,
		       unsigned char attn_reg)
{
   unsigned long flags;
   /* must wait for attention reg not busy */
   while (1) {
      IBMLOCK
      if (!(inb(IM_STAT_REG(host_index)) & IM_BUSY)) break;
      IBMUNLOCK
   }
   /* write registers and enable system interrupts */
   outl (cmd_reg, IM_CMD_REG(host_index));
   outb (attn_reg, IM_ATTN_REG(host_index));
   IBMUNLOCK
   return;
}

static void internal_done (Scsi_Cmnd * cmd)
{
   cmd->SCp.Status++;
   return;
}

/* SCSI-SCB-command for device_inquiry */
static int device_inquiry(int host_index, int ldn)
{
   int retr;
   struct im_scb *scb;
   struct im_tsb *tsb;
   unsigned char *buf;

   scb = &(ld(host_index)[ldn].scb);
   tsb = &(ld(host_index)[ldn].tsb);
   buf = (unsigned char *)(&(ld(host_index)[ldn].buf));
   ld(host_index)[ldn].tsb.dev_status = 0; /* prepare statusblock */
   for (retr=0; retr<3; retr++) {
      /* fill scb with inquiry command */
      scb->command = IM_DEVICE_INQUIRY_CMD | IM_NO_DISCONNECT;
      scb->enable = IM_REPORT_TSB_ONLY_ON_ERROR | IM_READ_CONTROL | IM_SUPRESS_EXCEPTION_SHORT | IM_RETRY_ENABLE | IM_BYPASS_BUFFER;
      last_scsi_command(host_index)[ldn] = IM_DEVICE_INQUIRY_CMD;
      last_scsi_type(host_index)[ldn] = IM_SCB;
      scb->sys_buf_adr = virt_to_bus(buf);
      scb->sys_buf_length = 255; /* maximum bufferlength gives max info */
      scb->tsb_adr = virt_to_bus(tsb);
      /* issue scb to passed ldn, and busy wait for interrupt */
      got_interrupt(host_index) = 0;
      issue_cmd (host_index, virt_to_bus(scb), IM_SCB | ldn);
      while (!got_interrupt(host_index))
	barrier ();

      /*if command succesful, break */
      if ((stat_result(host_index) == IM_SCB_CMD_COMPLETED)||
	  (stat_result(host_index) == IM_SCB_CMD_COMPLETED_WITH_RETRIES))
	return 1;
   }
   /*if all three retries failed, return "no device at this ldn" */
   if (retr >= 3)
     return 0;
   else
     return 1;
}

static int read_capacity(int host_index, int ldn)
{
   int retr;
   struct im_scb *scb;
   struct im_tsb *tsb;
   unsigned char *buf;

   scb = &(ld(host_index)[ldn].scb);
   tsb = &(ld(host_index)[ldn].tsb);
   buf = (unsigned char *)(&(ld(host_index)[ldn].buf));
   ld(host_index)[ldn].tsb.dev_status = 0;
   for (retr=0; retr<3; retr++) {
      /*fill scb with read capacity command */
      scb->command = IM_READ_CAPACITY_CMD;
      scb->enable = IM_REPORT_TSB_ONLY_ON_ERROR | IM_READ_CONTROL | IM_RETRY_ENABLE | IM_BYPASS_BUFFER;
      last_scsi_command(host_index)[ldn] = IM_READ_CAPACITY_CMD;
      last_scsi_type(host_index)[ldn] = IM_SCB;
      scb->sys_buf_adr = virt_to_bus(buf);
      scb->sys_buf_length = 8;
      scb->tsb_adr = virt_to_bus(tsb);
      /*issue scb to passed ldn, and busy wait for interrupt */
      got_interrupt(host_index) = 0;
      issue_cmd (host_index, virt_to_bus(scb), IM_SCB | ldn);
      while (!got_interrupt(host_index))
	barrier ();

      /*if got capacity, get block length and return one device found */
      if ((stat_result(host_index) == IM_SCB_CMD_COMPLETED)||
	  (stat_result(host_index) == IM_SCB_CMD_COMPLETED_WITH_RETRIES))
	return 1;
   }
   /*if all three retries failed, return "no device at this ldn" */
   if (retr >= 3)
     return 0;
   else
     return 1;
}

static int get_pos_info(int host_index)
{
   int retr;
   struct im_scb *scb;
   struct im_tsb *tsb;
   unsigned char *buf;

   scb = &(ld(host_index)[MAX_LOG_DEV].scb);
   tsb = &(ld(host_index)[MAX_LOG_DEV].tsb);
   buf = (unsigned char *)(&(ld(host_index)[MAX_LOG_DEV].buf));
   ld(host_index)[MAX_LOG_DEV].tsb.dev_status = 0;
   for (retr=0; retr<3; retr++) {
      /*fill scb with get_pos_info command */
      scb->command = IM_GET_POS_INFO_CMD;
      scb->enable = IM_READ_CONTROL | IM_REPORT_TSB_ONLY_ON_ERROR | IM_RETRY_ENABLE | IM_BYPASS_BUFFER;
      last_scsi_command(host_index)[MAX_LOG_DEV] = IM_GET_POS_INFO_CMD;
      last_scsi_type(host_index)[MAX_LOG_DEV] = IM_SCB;
      scb->sys_buf_adr = virt_to_bus(buf);
      if (special(host_index)==IBM_SCSI2_FW)
	scb->sys_buf_length = 256; /* get all info from F/W adapter */
      else
	scb->sys_buf_length = 18; /* get exactly 18 bytes for other SCSI */
      scb->tsb_adr = virt_to_bus(tsb);
      /*issue scb to ldn=15, and busy wait for interrupt */
      got_interrupt(host_index) = 0;
      issue_cmd (host_index, virt_to_bus(scb), IM_SCB | MAX_LOG_DEV);
      while (!got_interrupt(host_index))
	barrier ();

      /*if got POS-stuff, get block length and return one device found */
      if ((stat_result(host_index) == IM_SCB_CMD_COMPLETED)||
	  (stat_result(host_index) == IM_SCB_CMD_COMPLETED_WITH_RETRIES))
	return 1;
   }
   /* if all three retries failed, return "no device at this ldn" */
   if (retr >= 3)
     return 0;
   else
     return 1;
}

/* SCSI-immediate-command for assign. This functions maps/unmaps specific
 ldn-numbers on SCSI (PUN,LUN). It is needed for presetting of the
 subsystem and for dynamical remapping od ldns. */
static int immediate_assign(int host_index, unsigned int pun,
                            unsigned int lun, unsigned int ldn,
                            unsigned int operation)
{
   int retr;
   unsigned long imm_cmd;

   for (retr=0; retr<3; retr++) {
      /* select mutation level of the SCSI-adapter */
      switch (special(host_index)) {
       case IBM_SCSI2_FW:
	 imm_cmd = (unsigned long)(IM_ASSIGN_IMM_CMD);
	 imm_cmd |= (unsigned long)((lun & 7) << 24);
	 imm_cmd |= (unsigned long)((operation & 1) << 23);
	 imm_cmd |= (unsigned long)((pun & 7)<< 20)|((pun & 8)<< 24);
	 imm_cmd |= (unsigned long)((ldn & 15) << 16);
	 break;
       default:
	 imm_cmd = inl(IM_CMD_REG(host_index));
	 imm_cmd &= (unsigned long)(0xF8000000); /* keep reserved bits */
	 imm_cmd |= (unsigned long)(IM_ASSIGN_IMM_CMD);
	 imm_cmd |= (unsigned long)((lun & 7) << 24);
	 imm_cmd |= (unsigned long)((operation & 1) << 23);
	 imm_cmd |= (unsigned long)((pun & 7) << 20);
	 imm_cmd |= (unsigned long)((ldn & 15) << 16);
	 break;
      }
      last_scsi_command(host_index)[MAX_LOG_DEV] = IM_ASSIGN_IMM_CMD;
      last_scsi_type(host_index)[MAX_LOG_DEV] = IM_IMM_CMD;
      got_interrupt(host_index) = 0;
      issue_cmd (host_index, (unsigned long)(imm_cmd), IM_IMM_CMD | MAX_LOG_DEV);
      while (!got_interrupt(host_index))
	barrier ();

      /*if command succesful, break */
      if (stat_result(host_index) == IM_IMMEDIATE_CMD_COMPLETED)
	return 1;
   }
   if (retr >= 3)
     return 0;
   else
     return 1;
}

static int immediate_feature(int host_index, unsigned int speed,
			     unsigned int timeout)
{
   int retr;
   unsigned long imm_cmd;

   for (retr=0; retr<3; retr++) {
      /* select mutation level of the SCSI-adapter */
      imm_cmd  = IM_FEATURE_CTR_IMM_CMD;
      imm_cmd |= (unsigned long)((speed & 0x7) << 29);
      imm_cmd |= (unsigned long)((timeout & 0x1fff) << 16);
      last_scsi_command(host_index)[MAX_LOG_DEV] = IM_FEATURE_CTR_IMM_CMD;
      last_scsi_type(host_index)[MAX_LOG_DEV] = IM_IMM_CMD;
      got_interrupt(host_index) = 0;
      /* we need to run into command errors in order to probe for the
       * right speed! */
      global_command_error_excuse = 1;
      issue_cmd (host_index, (unsigned long)(imm_cmd), IM_IMM_CMD | MAX_LOG_DEV);
      while (!got_interrupt(host_index))
	barrier ();
      if (global_command_error_excuse == CMD_FAIL) {
	 global_command_error_excuse = 0;
	 return 2;
      } else
	global_command_error_excuse = 0;
      /*if command succesful, break */
      if (stat_result(host_index) == IM_IMMEDIATE_CMD_COMPLETED)
	return 1;
   }
   if (retr >= 3)
     return 0;
   else
     return 1;
}

#ifdef CONFIG_IBMMCA_SCSI_DEV_RESET
static int immediate_reset(int host_index, unsigned int ldn)
{
   int retries;
   int ticks;
   unsigned long imm_command;

   for (retries=0; retries<3; retries ++) {
      imm_command = inl(IM_CMD_REG(host_index));
      imm_command &= (unsigned long)(0xFFFF0000); /* keep reserved bits */
      imm_command |= (unsigned long)(IM_RESET_IMM_CMD);
      last_scsi_command(host_index)[ldn] = IM_RESET_IMM_CMD;
      last_scsi_type(host_index)[ldn] = IM_IMM_CMD;
      got_interrupt(host_index) = 0;
      reset_status(host_index) = IM_RESET_IN_PROGRESS;
      issue_cmd (host_index, (unsigned long)(imm_command), IM_IMM_CMD | ldn);
      ticks = IM_RESET_DELAY*HZ;
      while (reset_status(host_index) == IM_RESET_IN_PROGRESS && --ticks) {
	 udelay((1+999/HZ)*1000);
	 barrier();
      }
      /* if reset did not complete, just complain */
      if (!ticks) {
	 printk("IBM MCA SCSI: reset did not complete within %d seconds.\n",
		IM_RESET_DELAY);
	 reset_status(host_index) = IM_RESET_FINISHED_OK;
	 /* did not work, finish */
	 return 1;
      }
      /*if command succesful, break */
      if (stat_result(host_index) == IM_IMMEDIATE_CMD_COMPLETED)
	return 1;
   }
   if (retries >= 3)
     return 0;
   else
     return 1;
}
#endif

/* type-interpreter for physical device numbers */
static char *ti_p(int dev)
{
   switch (dev) {
    case TYPE_IBM_SCSI_ADAPTER: return("A");
    case TYPE_DISK:             return("D");
    case TYPE_TAPE:             return("T");
    case TYPE_PROCESSOR:        return("P");
    case TYPE_WORM:             return("W");
    case TYPE_ROM:              return("R");
    case TYPE_SCANNER:          return("S");
    case TYPE_MOD:              return("M");
    case TYPE_MEDIUM_CHANGER:   return("C");
    case TYPE_NO_LUN:           return("+"); /* show NO_LUN */
   }
   return("-"); /* TYPE_NO_DEVICE and others */
}

/* interpreter for logical device numbers (ldn) */
static char *ti_l(int val)
{
   const char hex[16] = "0123456789abcdef";
   static char answer[2];

   answer[1] = (char)(0x0);
   if (val<=MAX_LOG_DEV) answer[0] = hex[val]; else answer[0] = '-';
   return (char *)&answer;
}

/* transfers bitpattern of the feature command to values in MHz */
static char *ibmrate(unsigned int speed, int i)
{
   switch (speed) {
    case 0: return i ? "5.00" : "10.00";
    case 1: return i ? "4.00" : "8.00";
    case 2: return i ? "3.33" : "6.66";
    case 3: return i ? "2.86" : "5.00";
    case 4: return i ? "2.50" : "4.00";
    case 5: return i ? "2.22" : "3.10";
    case 6: return i ? "2.00" : "2.50";
    case 7: return i ? "1.82" : "2.00";
   }
   return "---";
}

static int probe_display(int what)
{
   static int rotator = 0;
   const char rotor[] = "|/-\\";

   if (!(display_mode & LED_DISP))
     return 0;
   if (!what) {
      outl(0x20202020,MOD95_LED_PORT);
      outl(0x20202020,MOD95_LED_PORT+4);
   } else {
      outb('S',MOD95_LED_PORT+7); outb('C',MOD95_LED_PORT+6);
      outb('S',MOD95_LED_PORT+5); outb('I',MOD95_LED_PORT+4);
      outb('i',MOD95_LED_PORT+3); outb('n',MOD95_LED_PORT+2);
      outb('i',MOD95_LED_PORT+1); outb((char)(rotor[rotator]),MOD95_LED_PORT);
      rotator++;
      if (rotator>3) rotator=0;
   }
   return 0;
}

static int probe_bus_mode(int host_index)
{
   struct im_pos_info *info;
   int num_bus = 0;
   int ldn;

   info = (struct im_pos_info *)(&(ld(host_index)[MAX_LOG_DEV].buf));
   if (get_pos_info(host_index)) {
      if (info->connector_size & 0xf000)
	subsystem_connector_size(host_index)=16;
      else
	subsystem_connector_size(host_index)=32;
      num_bus |= (info->pos_4b & 8) >> 3;
      for (ldn=0; ldn<=MAX_LOG_DEV; ldn++) {
	 if ((special(host_index)==IBM_SCSI_WCACHE)||
	     (special(host_index)==IBM_7568_WCACHE)) {
	    if (!((info->cache_stat >> ldn) & 1))
	      ld(host_index)[ldn].cache_flag = 0;
	 }
	 if (!((info->retry_stat >> ldn) & 1))
	   ld(host_index)[ldn].retry_flag = 0;
      }
#ifdef IM_DEBUG_PROBE
      printk("IBM MCA SCSI: SCSI-Cache bits: ");
      for (ldn=0; ldn<=MAX_LOG_DEV; ldn++) {
	 printk("%d",ld(host_index)[ldn].cache_flag);
      }
      printk("\nIBM MCA SCSI: SCSI-Retry bits: ");
      for (ldn=0; ldn<=MAX_LOG_DEV; ldn++) {
	 printk("%d",ld(host_index)[ldn].retry_flag);
      }
      printk("\n");
#endif
   }
   return num_bus;
}

/* probing scsi devices */
static void check_devices (int host_index, int adaptertype)
{
   int id, lun, ldn, ticks;
   int count_devices; /* local counter for connected device */
   int max_pun;
   int num_bus;
   int speedrun; /* local adapter_speed check variable */

   /* assign default values to certain variables */
   ticks = 0;
   count_devices = 0;
   IBM_DS(host_index).dyn_flag = 0; /* normally no need for dynamical ldn management */
   IBM_DS(host_index).total_errors = 0; /* set errorcounter to 0 */
   next_ldn(host_index) = 7; /* next ldn to be assigned is 7, because 0-6 is 'hardwired'*/

   /* initialize the very important driver-informational arrays/structs */
   memset (ld(host_index), 0, sizeof(ld(host_index)));
   for (ldn=0; ldn<=MAX_LOG_DEV; ldn++) {
      last_scsi_command(host_index)[ldn] = NO_SCSI; /* emptify last SCSI-command storage */
      last_scsi_type(host_index)[ldn] = 0;
      ld(host_index)[ldn].cache_flag = 1;
      ld(host_index)[ldn].retry_flag = 1;
   }
   memset (get_ldn(host_index), TYPE_NO_DEVICE, sizeof(get_ldn(host_index))); /* this is essential ! */
   memset (get_scsi(host_index), TYPE_NO_DEVICE, sizeof(get_scsi(host_index))); /* this is essential ! */
   for (lun=0; lun<8; lun++) {
      /* mark the adapter at its pun on all luns*/
      get_scsi(host_index)[subsystem_pun(host_index)][lun] = TYPE_IBM_SCSI_ADAPTER;
      get_ldn(host_index)[subsystem_pun(host_index)][lun] = MAX_LOG_DEV; /* make sure, the subsystem
									  ldn is active for all
									  luns. */
   }
   probe_display(0); /* Supercool display usage during SCSI-probing. */
                     /* This makes sense, when booting without any */
                     /* monitor connected on model XX95. */

   /* STEP 1: */
   adapter_speed(host_index) = global_adapter_speed;
   speedrun = adapter_speed(host_index);
   while (immediate_feature(host_index,speedrun,adapter_timeout)==2) {
      probe_display(1);
      if (speedrun==7)
	panic("IBM MCA SCSI: Cannot set Synchronous-Transfer-Rate!\n");
      speedrun++;
      if (speedrun>7)
	speedrun=7;
   }
   adapter_speed(host_index) = speedrun;
   /* Get detailed information about the current adapter, necessary for
    * device operations: */
   num_bus=probe_bus_mode(host_index);

   /* num_bus contains only valid data for the F/W adapter! */
   if (adaptertype==IBM_SCSI2_FW) { /* F/W SCSI adapter: */
      /* F/W adapter PUN-space extension evaluation: */
      if (num_bus) {
	 printk("IBM MCA SCSI: Seperate bus mode (wide-addressing enabled)\n");
	 subsystem_maxid(host_index) = 16;
      }	else {
	 printk("IBM MCA SCSI: Combined bus mode (wide-addressing disabled)\n");
	 subsystem_maxid(host_index) = 8;
      }
      printk("IBM MCA SCSI: Sync.-Rate (F/W: 20, Int.: 10, Ext.: %s) MBytes/s\n",
	     ibmrate(speedrun,adaptertype));
   } else /* all other IBM SCSI adapters: */
     printk("IBM MCA SCSI: Synchronous-SCSI-Transfer-Rate: %s MBytes/s\n",
	    ibmrate(speedrun,adaptertype));

   /* assign correct PUN device space */
   max_pun = subsystem_maxid(host_index);

#ifdef IM_DEBUG_PROBE
   printk("IBM MCA SCSI: Current SCSI-host index: %d\n",host_index);
   printk("IBM MCA SCSI: Removing default logical SCSI-device mapping.");
#else
   printk("IBM MCA SCSI: Dev. Order: %s, Mapping (takes <2min): ",
	  (ibm_ansi_order) ? "ANSI" : "New");
#endif
   for (ldn=0; ldn<MAX_LOG_DEV; ldn++) {
      probe_display(1);
#ifdef IM_DEBUG_PROBE
      printk(".");
#endif
      immediate_assign(host_index,0,0,ldn,REMOVE_LDN); /* remove ldn (wherever)*/
   }
   lun = 0; /* default lun is 0 */
#ifndef IM_DEBUG_PROBE
   printk("cleared,");
#endif
   /* STEP 2: */
#ifdef IM_DEBUG_PROBE
   printk("\nIBM MCA SCSI: Scanning SCSI-devices.");
#endif
   for (id=0; id<max_pun ; id++)
#ifdef CONFIG_SCSI_MULTI_LUN
     for (lun=0; lun<8; lun++)
#endif
     {
	probe_display(1);
#ifdef IM_DEBUG_PROBE
	printk(".");
#endif
	if (id != subsystem_pun(host_index)) {
	   /* if pun is not the adapter: */
	   /* set ldn=0 to pun,lun*/
	   immediate_assign(host_index,id,lun,PROBE_LDN,SET_LDN);
	   if (device_inquiry(host_index, PROBE_LDN)) { /* probe device */
	      get_scsi(host_index)[id][lun]=
		(unsigned char)(ld(host_index)[PROBE_LDN].buf[0]);
	      /* entry, even for NO_LUN */
	      if (ld(host_index)[PROBE_LDN].buf[0] != TYPE_NO_LUN)
		count_devices++; /* a existing device is found */
	   }
	   /* remove ldn */
	   immediate_assign(host_index,id,lun,PROBE_LDN,REMOVE_LDN);
	}
     }
#ifndef IM_DEBUG_PROBE
   printk("scanned,");
#endif
   /* STEP 3: */
#ifdef IM_DEBUG_PROBE
   printk("\nIBM MCA SCSI: Mapping SCSI-devices.");
#endif
   ldn = 0;
   lun = 0;
#ifdef CONFIG_SCSI_MULTI_LUN
   for (lun=0; lun<8 && ldn<MAX_LOG_DEV; lun++)
#endif
     for (id=0; id<max_pun && ldn<MAX_LOG_DEV; id++) {
	probe_display(1);
#ifdef IM_DEBUG_PROBE
	printk(".");
#endif
	if (id != subsystem_pun(host_index)) {
	   if (get_scsi(host_index)[id][lun] != TYPE_NO_LUN &&
	       get_scsi(host_index)[id][lun] != TYPE_NO_DEVICE) {
	      /* Only map if accepted type. Always enter for
	       lun == 0 to get no gaps into ldn-mapping for ldn<7. */
	      immediate_assign(host_index,id,lun,ldn,SET_LDN);
	      get_ldn(host_index)[id][lun]=ldn; /* map ldn */
	      if (device_exists (host_index, ldn,
				 &ld(host_index)[ldn].block_length,
				 &ld(host_index)[ldn].device_type)) {
#ifdef CONFIG_IBMMCA_SCSI_DEV_RESET
		 printk("resetting device at ldn=%x ... ",ldn);
		 immediate_reset(host_index,ldn);
#endif
		 ldn++;
	      } else {
		 /* device vanished, probably because we don't know how to
		  * handle it or because it has problems */
		 if (lun > 0) {
		    /* remove mapping */
		    get_ldn(host_index)[id][lun]=TYPE_NO_DEVICE;
		    immediate_assign(host_index,0,0,ldn,REMOVE_LDN);
		 } else ldn++;
	      }
	   } else if (lun == 0) {
	      /* map lun == 0, even if no device exists */
	      immediate_assign(host_index,id,lun,ldn,SET_LDN);
	      get_ldn(host_index)[id][lun]=ldn; /* map ldn */
	      ldn++;
	   }
	}
     }
   /* STEP 4: */

   /* map remaining ldns to non-existing devices */
   for (lun=1; lun<8 && ldn<MAX_LOG_DEV; lun++)
     for (id=0; id<max_pun && ldn<MAX_LOG_DEV; id++) {
	if (get_scsi(host_index)[id][lun] == TYPE_NO_LUN ||
	    get_scsi(host_index)[id][lun] == TYPE_NO_DEVICE) {
	   probe_display(1);
	   /* Map remaining ldns only to NON-existing pun,lun
	    combinations to make sure an inquiry will fail.
	    For MULTI_LUN, it is needed to avoid adapter autonome
	    SCSI-remapping. */
	   immediate_assign(host_index,id,lun,ldn,SET_LDN);
	   get_ldn(host_index)[id][lun]=ldn;
	   ldn++;
	}
     }
#ifndef IM_DEBUG_PROBE
   printk("mapped.");
#endif
   printk("\n");
#ifdef IM_DEBUG_PROBE
   if (ibm_ansi_order)
     printk("IBM MCA SCSI: Device order: IBM/ANSI (pun=7 is first).\n");
   else
     printk("IBM MCA SCSI: Device order: New Industry Standard (pun=0 is first).\n");
#endif

#ifdef IM_DEBUG_PROBE
   /* Show the physical and logical mapping during boot. */
   printk("IBM MCA SCSI: Determined SCSI-device-mapping:\n");
   printk("    Physical SCSI-Device Map               Logical SCSI-Device Map\n");
   printk("ID\\LUN  0  1  2  3  4  5  6  7       ID\\LUN  0  1  2  3  4  5  6  7\n");
   for (id=0; id<max_pun; id++) {
      printk("%2d     ",id);
      for (lun=0; lun<8; lun++)
	printk("%2s ",ti_p(get_scsi(host_index)[id][lun]));
      printk("      %2d     ",id);
      for (lun=0; lun<8; lun++)
	printk("%2s ",ti_l(get_ldn(host_index)[id][lun]));
      printk("\n");
   }
#endif

   /* assign total number of found SCSI-devices to the statistics struct */
   IBM_DS(host_index).total_scsi_devices = count_devices;

   /* decide for output in /proc-filesystem, if the configuration of
      SCSI-devices makes dynamical reassignment of devices necessary */
   if (count_devices>=MAX_LOG_DEV)
     IBM_DS(host_index).dyn_flag = 1; /* dynamical assignment is necessary */
   else
     IBM_DS(host_index).dyn_flag = 0; /* dynamical assignment is not necessary */

   /* If no SCSI-devices are assigned, return 1 in order to cause message. */
   if (ldn == 0)
     printk("IBM MCA SCSI: Warning: No SCSI-devices found/assigned!\n");

   /* reset the counters for statistics on the current adapter */
   IBM_DS(host_index).scbs = 0;
   IBM_DS(host_index).long_scbs = 0;
   IBM_DS(host_index).total_accesses = 0;
   IBM_DS(host_index).total_interrupts = 0;
   IBM_DS(host_index).dynamical_assignments = 0;
   memset (IBM_DS(host_index).ldn_access, 0x0,
	   sizeof (IBM_DS(host_index).ldn_access));
   memset (IBM_DS(host_index).ldn_read_access, 0x0,
	   sizeof (IBM_DS(host_index).ldn_read_access));
   memset (IBM_DS(host_index).ldn_write_access, 0x0,
	   sizeof (IBM_DS(host_index).ldn_write_access));
   memset (IBM_DS(host_index).ldn_inquiry_access, 0x0,
	   sizeof (IBM_DS(host_index).ldn_inquiry_access));
   memset (IBM_DS(host_index).ldn_modeselect_access, 0x0,
	   sizeof (IBM_DS(host_index).ldn_modeselect_access));
   memset (IBM_DS(host_index).ldn_assignments, 0x0,
	   sizeof (IBM_DS(host_index).ldn_assignments));
   probe_display(0);
   return;
}

static int device_exists (int host_index, int ldn, int *block_length,
			  int *device_type)
{
   unsigned char *buf;
   /* if no valid device found, return immediately with 0 */
   if (!(device_inquiry(host_index, ldn)))
     return 0;
   buf = (unsigned char *)(&(ld(host_index)[ldn].buf));
   if (*buf == TYPE_ROM) {
      *device_type = TYPE_ROM;
      *block_length = 2048; /* (standard blocksize for yellow-/red-book) */
      return 1;
   }
   if (*buf == TYPE_WORM) {
      *device_type = TYPE_WORM;
      *block_length = 2048;
      return 1;
   }
   if (*buf == TYPE_DISK) {
      *device_type = TYPE_DISK;
      if (read_capacity( host_index, ldn)) {
	 *block_length = *(buf+7) + (*(buf+6) << 8) +
	   (*(buf+5) << 16) + (*(buf+4) << 24);
	 return 1;
      } else
	return 0;
   }
   if (*buf == TYPE_MOD) {
      *device_type = TYPE_MOD;
      if (read_capacity( host_index, ldn)) {
	 *block_length = *(buf+7) + (*(buf+6) << 8) +
	   (*(buf+5) << 16) + (*(buf+4) << 24);
	 return 1;
      } else
	return 0;
   }
   if (*buf == TYPE_TAPE) {
      *device_type = TYPE_TAPE;
      *block_length = 0; /* not in use (setting by mt and mtst in op.) */
      return 1;
   }
   if (*buf == TYPE_PROCESSOR) {
      *device_type = TYPE_PROCESSOR;
      *block_length = 0; /* they set their stuff on drivers */
      return 1;
   }
   if (*buf == TYPE_SCANNER) {
      *device_type = TYPE_SCANNER;
      *block_length = 0; /* they set their stuff on drivers */
      return 1;
   }
   if (*buf == TYPE_MEDIUM_CHANGER) {
      *device_type = TYPE_MEDIUM_CHANGER;
      *block_length = 0; /* One never knows, what to expect on a medium
			    changer device. */
      return 1;
   }
   return 0;
}

void internal_ibmmca_scsi_setup (char *str, int *ints)
{
   int i, j, io_base, id_base;
   char *token;

   io_base = 0;
   id_base = 0;
   if (str) {
      token = strtok(str,",");
      j = 0;
      while (token) {
	 if (!strcmp(token,"activity")) display_mode |= LED_ACTIVITY;
	 if (!strcmp(token,"display")) display_mode |= LED_DISP;
	 if (!strcmp(token,"adisplay")) display_mode |= LED_ADISP;
	 if (!strcmp(token,"normal")) ibm_ansi_order = 0;
	 if (!strcmp(token,"ansi")) ibm_ansi_order = 1;
	 if (!strcmp(token,"fast")) global_adapter_speed = 0;
	 if (!strcmp(token,"medium")) global_adapter_speed = 4;
	 if (!strcmp(token,"slow")) global_adapter_speed = 7;
	 if ((*token == '-') || (isdigit(*token))) {
	    if (!(j%2) && (io_base < IM_MAX_HOSTS))
	      io_port[io_base++] = simple_strtoul(token,NULL,0);
	    if ((j%2) && (id_base < IM_MAX_HOSTS))
	      scsi_id[id_base++] = simple_strtoul(token,NULL,0);
	    j++;
	 }
	 token = strtok(NULL,",");
      }
   } else if (ints) {
      for (i = 0; i < IM_MAX_HOSTS && 2*i+2 < ints[0]; i++) {
	 io_port[i] = ints[2*i+2];
	 scsi_id[i] = ints[2*i+2];
      }
   }
   return;
}

static int ibmmca_getinfo (char *buf, int slot, void *dev)
{
   struct Scsi_Host *shpnt;
   int len, speciale, connectore, k;
   unsigned int pos[8];
   unsigned long flags;

   IBMLOCK
   shpnt = dev; /* assign host-structure to local pointer */
   len = 0; /* set filled text-buffer index to 0 */
   /* get the _special contents of the hostdata structure */
   speciale = ((struct ibmmca_hostdata *)shpnt->hostdata)->_special;
   connectore = ((struct ibmmca_hostdata *)shpnt->hostdata)->_connector_size;
   for (k=2;k<4;k++)
     pos[k] = ((struct ibmmca_hostdata *)shpnt->hostdata)->_pos[k];
   if (speciale == FORCED_DETECTION) { /* forced detection */
      len += sprintf (buf+len,
		      "Adapter category: forced detected\n"
		      "***************************************\n"
		      "***  Forced detected SCSI Adapter   ***\n"
		      "***  No chip-information available  ***\n"
		      "***************************************\n");
   } else if (speciale == INTEGRATED_SCSI) {
      /* if the integrated subsystem has been found automatically: */
      len += sprintf (buf+len,
		      "Adapter category: integrated\n"
		      "Chip revision level: %d\n"
		      "Chip status: %s\n"
		      "8 kByte NVRAM status: %s\n",
		      ((pos[2] & 0xf0) >> 4),
		      (pos[2] & 1) ? "enabled" : "disabled",
		      (pos[2] & 2) ? "locked" : "accessible");
   } else if ((speciale>=0)&&
	      (speciale<(sizeof(subsys_list)/sizeof(struct subsys_list_struct)))) {
      /* if the subsystem is a slot adapter */
      len += sprintf (buf+len,
		      "Adapter category: slot-card\n"
		      "ROM Segment Address: ");
      if ((pos[2] & 0xf0) == 0xf0)
	len += sprintf (buf+len, "off\n");
      else
	len += sprintf (buf+len, "0x%x\n",
			((pos[2] & 0xf0) << 13) + 0xc0000);
      len += sprintf (buf + len, "Chip status: %s\n",
		      (pos[2] & 1) ? "enabled" : "disabled");
      len += sprintf (buf + len, "Adapter I/O Offset: 0x%x\n",
		      ((pos[2] & 0x0e) << 2));
   } else {
      len += sprintf (buf + len, "Adapter category: unknown\n");
   }
   /* common subsystem information to write to the slotn file */
   len += sprintf (buf + len, "Subsystem PUN: %d\n", shpnt->this_id);
   len += sprintf (buf + len, "I/O base address range: 0x%x-0x%x\n",
		   (unsigned int)(shpnt->io_port),
		   (unsigned int)(shpnt->io_port+7));
   len += sprintf (buf + len, "MCA-slot size: %d bits",connectore);
   /* Now make sure, the bufferlength is devidable by 4 to avoid
    * paging problems of the buffer. */
   while ( len % sizeof( int ) != ( sizeof ( int ) - 1 ) )
     len += sprintf (buf+len, " ");
   len += sprintf (buf+len, "\n");
   IBMUNLOCK
   return len;
}

int ibmmca_detect (Scsi_Host_Template * scsi_template)
{
   struct Scsi_Host *shpnt;
   int port, id, i, j, k, list_size, slot;
   int devices_on_irq_11 = 0;
   int devices_on_irq_14 = 0;
   int IRQ14_registered = 0;
   int IRQ11_registered = 0;

   found = 0; /* make absolutely sure, that found is set to 0 */

   /* First of all, print the version number of the driver. This is
    * important to allow better user bugreports in case of already
    * having problems with the MCA_bus probing. */
   printk("IBM MCA SCSI: Version %s\n",IBMMCA_SCSI_DRIVER_VERSION);
   /* if this is not MCA machine, return "nothing found" */
   if (!MCA_bus) {
      printk("IBM MCA SCSI:  No Microchannel-bus present --> Aborting.\n"
	     "      	     This machine does not have any IBM MCA-bus\n"
	     "    	     or the MCA-Kernel-support is not enabled!\n");
      return 0;
   }

#ifdef MODULE
   /* If the driver is run as module, read from conf.modules or cmd-line */
   if (boot_options) option_setup(boot_options);
#endif

   /* get interrupt request level */
   if (request_irq (IM_IRQ, interrupt_handler, SA_SHIRQ, "ibmmcascsi",
		    hosts)) {
      printk("IBM MCA SCSI: Unable to get shared IRQ %d.\n", IM_IRQ);
      return 0;
   } else
     IRQ14_registered++;

   /* if ibmmcascsi setup option was passed to kernel, return "found" */
   for (i = 0; i < IM_MAX_HOSTS; i++)
     if (io_port[i] > 0 && scsi_id[i] >= 0 && scsi_id[i] < 8) {
	printk("IBM MCA SCSI: forced detected SCSI Adapter, io=0x%x, scsi id=%d.\n",
	       io_port[i], scsi_id[i]);
	if ((shpnt = ibmmca_register(scsi_template, io_port[i], scsi_id[i],
		     FORCED_DETECTION, "forced detected SCSI Adapter"))) {
	   for (k=2;k<7;k++)
	     ((struct ibmmca_hostdata *)shpnt->hostdata)->_pos[k] = 0;
	   ((struct ibmmca_hostdata *)shpnt->hostdata)->_special = FORCED_DETECTION;
	   mca_set_adapter_name(MCA_INTEGSCSI, "forced detected SCSI Adapter");
	   mca_set_adapter_procfn(MCA_INTEGSCSI, (MCA_ProcFn) ibmmca_getinfo,
				  shpnt);
	   mca_mark_as_used(MCA_INTEGSCSI);
	   devices_on_irq_14++;
	}
     }
   if (found) return found;

   /* The POS2-register of all PS/2 model SCSI-subsystems has the following
    * interpretation of bits:
    *                             Bit 7 - 4 : Chip Revision ID (Release)
    *                             Bit 3 - 2 : Reserved
    *                             Bit 1     : 8k NVRAM Disabled
    *                             Bit 0     : Chip Enable (EN-Signal)
    * The POS3-register is interpreted as follows:
    *                             Bit 7 - 5 : SCSI ID
    *                             Bit 4     : Reserved = 0
    *                             Bit 3 - 0 : Reserved = 0
    * (taken from "IBM, PS/2 Hardware Interface Technical Reference, Common
    * Interfaces (1991)").
    * In short words, this means, that IBM PS/2 machines only support
    * 1 single subsystem by default. The slot-adapters must have another
    * configuration on pos2. Here, one has to assume the following
    * things for POS2-register:
    *                             Bit 7 - 4 : Chip Revision ID (Release)
    *                             Bit 3 - 1 : port offset factor
    *                             Bit 0     : Chip Enable (EN-Signal)
    * As I found a patch here, setting the IO-registers to 0x3540 forced,
    * as there was a 0x05 in POS2 on a model 56, I assume, that the
    * port 0x3540 must be fix for integrated SCSI-controllers.
    * Ok, this discovery leads to the following implementation: (M.Lang) */

   /* first look for the IBM SCSI integrated subsystem on the motherboard */
   for (j=0;j<8;j++) /* read the pos-information */
     pos[j] = mca_read_stored_pos(MCA_INTEGSCSI,j);
   /* pos2 = pos3 = 0xff if there is no integrated SCSI-subsystem present, but
    * if we ignore the settings of all surrounding pos registers, it is not
    * completely sufficient to only check pos2 and pos3. */
   /* Therefore, now the following if statement is used to
    * make sure, we see a real integrated onboard SCSI-interface and no
    * internal system information, which gets mapped to some pos registers
    * on models 95xx. */
   if ((!pos[0] && !pos[1] && pos[2]>0 && pos[3]>0 && !pos[4] && !pos[5] && !pos[6] && !pos[7]) ||
       (pos[0]==0xff && pos[1]==0xff && pos[2]<0xff && pos[3]<0xff && pos[4]==0xff && pos[5]==0xff && pos[6]==0xff && pos[7]==0xff)) {
      if ((pos[2] & 1) == 1) /* is the subsystem chip enabled ? */
	port = IM_IO_PORT;
      else { /* if disabled, no IRQs will be generated, as the chip won't
	      * listen to the incomming commands and will do really nothing,
	      * except for listening to the pos-register settings. If this
	      * happens, I need to hugely think about it, as one has to
	      * write something to the MCA-Bus pos register in order to
	      * enable the chip. Normally, IBM-SCSI won't pass the POST,
	      * when the chip is disabled (see IBM tech. ref.). */
	 port = IM_IO_PORT; /* anyway, set the portnumber and warn */
	 printk("IBM MCA SCSI: WARNING - Your SCSI-subsystem is disabled!\n"
		"              SCSI-operations may not work.\n");
      }
      id = (pos[3] & 0xe0) >> 5; /* this is correct and represents the PUN */
      /* give detailed information on the subsystem. This helps me
       * additionally during debugging and analyzing bug-reports. */
      printk("IBM MCA SCSI: IBM Integrated SCSI Controller found, io=0x%x, scsi id=%d,\n"
	     "              chip rev.=%d, 8K NVRAM=%s, subsystem=%s\n",
	     port, id,
	     ((pos[2] & 0xf0) >> 4), (pos[2] & 2) ? "locked" : "accessible",
	     (pos[2] & 1) ? "enabled." : "disabled.");

      /* register the found integrated SCSI-subsystem */
      if ((shpnt = ibmmca_register(scsi_template, port, id, INTEGRATED_SCSI,
				   "IBM Integrated SCSI Controller"))) {
	 for (k=2;k<7;k++)
	   ((struct ibmmca_hostdata *)shpnt->hostdata)->_pos[k] = pos[k];
	 ((struct ibmmca_hostdata *)shpnt->hostdata)->_special = INTEGRATED_SCSI;
	 mca_set_adapter_name(MCA_INTEGSCSI, "IBM Integrated SCSI Controller");
	 mca_set_adapter_procfn(MCA_INTEGSCSI, (MCA_ProcFn) ibmmca_getinfo,
				shpnt);
	 mca_mark_as_used(MCA_INTEGSCSI);
	 devices_on_irq_14++;
      }
   }

   /* now look for other adapters in MCA slots, */
   /* determine the number of known IBM-SCSI-subsystem types */
   /* see the pos[2] dependence to get the adapter port-offset. */
   list_size = sizeof(subsys_list) / sizeof(struct subsys_list_struct);
   for (i = 0; i < list_size; i++) {
      /* scan each slot for a fitting adapter id */
      slot = 0; /* start at slot 0 */
      while ((slot = mca_find_adapter(subsys_list[i].mca_id, slot))
	     != MCA_NOTFOUND) { /* scan through all slots */
	 for (j=0;j<8;j++) /* read the pos-information */
	   pos[j] = mca_read_stored_pos(slot, j);
	 if ((pos[2] & 1) == 1) /* is the subsystem chip enabled ? */
	   /* (explanations see above) */
	   port = IM_IO_PORT + ((pos[2] & 0x0e) << 2);
	 else {
	    /* anyway, set the portnumber and warn */
	    port = IM_IO_PORT + ((pos[2] & 0x0e) << 2);
	    printk("IBM MCA SCSI: WARNING - Your SCSI-subsystem is disabled!\n"
		   "              SCSI-operations may not work.\n");
	 }
	 if ((i==IBM_SCSI2_FW)&&(pos[6]!=0)) {
	    printk("IBM MCA SCSI: ERROR - Wrong POS(6)-register setting!\n"
		   "              Impossible to determine adapter PUN!\n"
		   "              Guessing adapter PUN = 7.\n");
	    id = 7;
	 } else {
	    id = (pos[3] & 0xe0) >> 5; /* get subsystem PUN */
	    if (i==IBM_SCSI2_FW) {
	       id |= (pos[3] & 0x10) >> 1; /* get subsystem PUN high-bit
					    * for F/W adapters */
	    }
	 }
	 if ((i==IBM_SCSI2_FW)&&(pos[4] & 0x01)&&(pos[6]==0)) {
	    /* IRQ11 is used by SCSI-2 F/W Adapter/A */
	    printk("IBM MCA SCSI: SCSI-2 F/W adapter needs IRQ 11.\n");
	    /* get interrupt request level */
	    if (request_irq (IM_IRQ_FW, interrupt_handler, SA_SHIRQ,
			     "ibmmcascsi", hosts)) {
	       printk("IBM MCA SCSI: Unable to get shared IRQ %d.\n",
		      IM_IRQ_FW);
	    } else
	      IRQ11_registered++;
	 }
	 printk("IBM MCA SCSI: %s found in slot %d, io=0x%x, scsi id=%d,\n",
		subsys_list[i].description, slot + 1, port, id);
	 if ((pos[2] & 0xf0) == 0xf0)
	   printk("              ROM Addr.=off,");
	 else
	   printk("              ROM Addr.=0x%x,",
		  ((pos[2] & 0xf0) << 13) + 0xc0000);
	 printk(" port-offset=0x%x, subsystem=%s\n",
		((pos[2] & 0x0e) << 2),
		(pos[2] & 1) ? "enabled." : "disabled.");

	 /* register the hostadapter */
	 if ((shpnt = ibmmca_register(scsi_template, port, id, i,
				      subsys_list[i].description))) {
	    for (k=2;k<8;k++)
	      ((struct ibmmca_hostdata *)shpnt->hostdata)->_pos[k] = pos[k];
	    ((struct ibmmca_hostdata *)shpnt->hostdata)->_special = i;
	    mca_set_adapter_name (slot, subsys_list[i].description);
	    mca_set_adapter_procfn (slot, (MCA_ProcFn) ibmmca_getinfo,
				    shpnt);
	    mca_mark_as_used(slot);
	    if ((i==IBM_SCSI2_FW)&&(pos[4] & 0x01)&&(pos[6]==0))
	      devices_on_irq_11++;
	    else
	      devices_on_irq_14++;
	 }
	 slot++; /* advance to next slot */
      } /* advance to next adapter id in the list of IBM-SCSI-subsystems*/
   }

   /* now check for SCSI-adapters, mapped to the integrated SCSI
    * area. E.g. a W/Cache in MCA-slot 9(!). Do the check correct here,
    * as this is a known effect on some models 95xx. */
   list_size = sizeof(subsys_list) / sizeof(struct subsys_list_struct);
   for (i = 0; i < list_size; i++) {
      /* scan each slot for a fitting adapter id */
      slot = mca_find_adapter(subsys_list[i].mca_id, MCA_INTEGSCSI);
      if (slot != MCA_NOTFOUND) { /* scan through all slots */
	 for (j=0;j<8;j++) /* read the pos-information */
	   pos[j] = mca_read_stored_pos(slot, j);
	 if ((pos[2] & 1) == 1) { /* is the subsystem chip enabled ? */
	    /* (explanations see above) */
	    port = IM_IO_PORT + ((pos[2] & 0x0e) << 2);
	 } else { /* anyway, set the portnumber and warn */
	    port = IM_IO_PORT + ((pos[2] & 0x0e) << 2);
	    printk("IBM MCA SCSI: WARNING - Your SCSI-subsystem is disabled!\n"
		   "              SCSI-operations may not work.\n");
	 }
	 if ((i==IBM_SCSI2_FW)&&(pos[6]!=0)) {
	    printk("IBM MCA SCSI: ERROR - Wrong POS(6)-register setting!\n"
		   "              Impossible to determine adapter PUN!\n"
		   "              Guessing adapter PUN = 7.\n");
	    id = 7;
	 } else {
	    id = (pos[3] & 0xe0) >> 5; /* get subsystem PUN */
	    if (i==IBM_SCSI2_FW)
	      id |= (pos[3] & 0x10) >> 1; /* get subsystem PUN high-bit
					   * for F/W adapters */
	 }
	 if ((i==IBM_SCSI2_FW)&&(pos[4] & 0x01)&&(pos[6]==0)) {
	    /* IRQ11 is used by SCSI-2 F/W Adapter/A */
	    printk("IBM MCA SCSI: SCSI-2 F/W adapter needs IRQ 11.\n");
	    /* get interrupt request level */
	    if (request_irq (IM_IRQ_FW, interrupt_handler, SA_SHIRQ,
			     "ibmmcascsi", hosts))
	      printk("IBM MCA SCSI: Unable to get shared IRQ %d.\n",
		     IM_IRQ_FW);
	    else
	      IRQ11_registered++;
	 }
	 printk("IBM MCA SCSI: %s found in slot %d, io=0x%x, scsi id=%d,\n",
		subsys_list[i].description, slot + 1, port, id);
	 if ((pos[2] & 0xf0) == 0xf0)
	   printk("              ROM Addr.=off,");
	 else
	   printk("              ROM Addr.=0x%x,",
		  ((pos[2] & 0xf0) << 13) + 0xc0000);
	 printk(" port-offset=0x%x, subsystem=%s\n",
		((pos[2] & 0x0e) << 2),
		(pos[2] & 1) ? "enabled." : "disabled.");

	 /* register the hostadapter */
	 if ((shpnt = ibmmca_register(scsi_template, port, id, i,
				      subsys_list[i].description))) {
	    for (k=2;k<7;k++)
	      ((struct ibmmca_hostdata *)shpnt->hostdata)->_pos[k] = pos[k];
	    ((struct ibmmca_hostdata *)shpnt->hostdata)->_special = i;
	    mca_set_adapter_name (slot, subsys_list[i].description);
	    mca_set_adapter_procfn (slot, (MCA_ProcFn) ibmmca_getinfo, shpnt);
	    mca_mark_as_used(slot);
	    if ((i==IBM_SCSI2_FW)&&(pos[4] & 0x01)&&(pos[6]==0))
	      devices_on_irq_11++;
	    else
	      devices_on_irq_14++;
	 }
	 slot++; /* advance to next slot */
      } /* advance to next adapter id in the list of IBM-SCSI-subsystems*/
   }
   if ( IRQ11_registered && !devices_on_irq_11 )
     free_irq(IM_IRQ_FW, hosts); /* no devices on IRQ 11 */
   if ( IRQ14_registered && !devices_on_irq_14 )
     free_irq(IM_IRQ, hosts); /* no devices on IRQ 14 */
   if ( !devices_on_irq_11 && !devices_on_irq_14 )
     printk("IBM MCA SCSI: No IBM SCSI-subsystem adapter attached.\n");
   return found; /* return the number of found SCSI hosts. Should be 1 or 0. */
}

static struct Scsi_Host *
ibmmca_register(Scsi_Host_Template * scsi_template, int port, int id,
		int adaptertype, char *hostname)
{
   struct Scsi_Host *shpnt;
   int i, j;
   unsigned int ctrl;

   /* check I/O region */
   if (check_region(port, IM_N_IO_PORT)) {
      printk("IBM MCA SCSI: Unable to get I/O region 0x%x-0x%x (%d ports).\n",
	     port, port + IM_N_IO_PORT - 1, IM_N_IO_PORT);
      return NULL;
   }

   /* register host */
   shpnt = scsi_register(scsi_template, sizeof(struct ibmmca_hostdata));
   if (!shpnt) {
      printk("IBM MCA SCSI: Unable to register host.\n");
      return NULL;
   }

   /* request I/O region */
   request_region(port, IM_N_IO_PORT, hostname);
   hosts[found] = shpnt; /* add new found hostadapter to the list */
   special(found) = adaptertype; /* important assignment or else crash! */
   subsystem_connector_size(found) = 0; /* preset slot-size */
   shpnt->irq = IM_IRQ; /* assign necessary stuff for the adapter */
   shpnt->io_port = port;
   shpnt->n_io_port = IM_N_IO_PORT;
   shpnt->this_id = id;
   shpnt->max_id = 8; /* 8 PUNs are default */
   /* now, the SCSI-subsystem is connected to Linux */

   ctrl = (unsigned int)(inb(IM_CTR_REG(found))); /* get control-register status */
#ifdef IM_DEBUG_PROBE
   printk("IBM MCA SCSI: Control Register contents: %x, status: %x\n",
	  ctrl,inb(IM_STAT_REG(found)));
   printk("IBM MCA SCSI: This adapters' POS-registers: ");
   for (i=0;i<8;i++)
     printk("%x ",pos[i]);
   printk("\n");
#endif
   reset_status(found) = IM_RESET_NOT_IN_PROGRESS;

   for (i = 0; i < 16; i++) /* reset the tables */
     for (j = 0; j < 8; j++)
     get_ldn(found)[i][j] = MAX_LOG_DEV;

   /* check which logical devices exist */
   /* after this line, local interrupting is possible: */
   local_checking_phase_flag(found) = 1;
   check_devices(found,adaptertype); /* call by value, using the global variable hosts*/
   local_checking_phase_flag(found) = 0;
   found++; /* now increase index to be prepared for next found subsystem */
   /* an ibm mca subsystem has been detected */
   return shpnt;
}

int ibmmca_command (Scsi_Cmnd * cmd)
{
  ibmmca_queuecommand (cmd, internal_done);
  cmd->SCp.Status = 0;
  while (!cmd->SCp.Status) barrier ();
  return cmd->result;
}

int ibmmca_release(struct Scsi_Host *shpnt)
{
  release_region(shpnt->io_port, shpnt->n_io_port);
  if (!(--found)) free_irq(shpnt->irq, hosts);
  return 0;
}

/* The following routine is the SCSI command queue for the midlevel driver */
int ibmmca_queuecommand (Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
{
   unsigned int ldn;
   unsigned int scsi_cmd;
   struct im_scb *scb;
   struct Scsi_Host *shpnt;
   int current_ldn;
   int id,lun;
   int target;
   int host_index;
   int max_pun;
   int i;
   struct scatterlist *sl;

   shpnt = cmd->host;
   /* search for the right hostadapter */
   for (host_index = 0; hosts[host_index] && hosts[host_index]->host_no != shpnt->host_no; host_index++);

   if (!hosts[host_index]) { /* invalid hostadapter descriptor address */
      cmd->result = DID_NO_CONNECT << 16;
      if (done) done (cmd);
      return 0;
   }
   max_pun = subsystem_maxid(host_index);
   if (ibm_ansi_order) {
      target = max_pun - 1 - cmd->target;
      if ((target <= subsystem_pun(host_index))&&(cmd->target <= subsystem_pun(host_index)))
	target--;
      else if ((target >= subsystem_pun(host_index))&&(cmd->target >= subsystem_pun(host_index)))
	target++;
   } else
     target = cmd->target;

   /* if (target,lun) is NO LUN or not existing at all, return error */
   if ((get_scsi(host_index)[target][cmd->lun] == TYPE_NO_LUN)||
       (get_scsi(host_index)[target][cmd->lun] == TYPE_NO_DEVICE)) {
      cmd->result = DID_NO_CONNECT << 16;
      if (done) done (cmd);
      return 0;
   }

   /*if (target,lun) unassigned, do further checks... */
   ldn = get_ldn(host_index)[target][cmd->lun];
   if (ldn >= MAX_LOG_DEV) { /* on invalid ldn do special stuff */
      if (ldn > MAX_LOG_DEV) { /* dynamical remapping if ldn unassigned */
	 current_ldn = next_ldn(host_index); /* stop-value for one circle */
	 while (ld(host_index)[next_ldn(host_index)].cmd) { /* search for a occupied, but not in */
	    /* command-processing ldn. */
	    next_ldn(host_index)++;
	    if (next_ldn(host_index)>=MAX_LOG_DEV)
	      next_ldn(host_index) = 7;
	    if (current_ldn == next_ldn(host_index)) { /* One circle done ? */
	       /* no non-processing ldn found */
	       printk("IBM MCA SCSI: Cannot assign SCSI-device dynamically!\n" \
		      "              On ldn 7-14 SCSI-commands everywhere in progress.\n" \
		      "              Reporting DID_NO_CONNECT for device (%d,%d).\n",
		      target, cmd->lun);
	       cmd->result = DID_NO_CONNECT << 16;/* return no connect*/
	       if (done) done (cmd);
	       return 0;
	    }
	 }

	 /* unmap non-processing ldn */
	 for (id=0; id<max_pun; id ++)
	   for (lun=0; lun<8; lun++) {
	      if (get_ldn(host_index)[id][lun] == next_ldn(host_index)) {
		 get_ldn(host_index)[id][lun] = TYPE_NO_DEVICE;
		 get_scsi(host_index)[id][lun] = TYPE_NO_DEVICE;
		 /* unmap entry */
	      }
	   }
	 /* set reduced interrupt_handler-mode for checking */
	 local_checking_phase_flag(host_index) = 1;
	 /* map found ldn to pun,lun */
	 get_ldn(host_index)[target][cmd->lun] = next_ldn(host_index);
	 /* change ldn to the right value, that is now next_ldn */
	 ldn = next_ldn(host_index);
	 /* unassign all ldns (pun,lun,ldn does not matter for remove) */
	 immediate_assign(host_index,0,0,0,REMOVE_LDN);
	 /* set only LDN for remapped device */
	 immediate_assign(host_index,target,cmd->lun,ldn,SET_LDN);
	 /* get device information for ld[ldn] */
	 if (device_exists (host_index, ldn,
			    &ld(host_index)[ldn].block_length,
			    &ld(host_index)[ldn].device_type)) {
	    ld(host_index)[ldn].cmd = NULL; /* To prevent panic set 0, because
					       devices that were not assigned,
					       should have nothing in progress. */
	    get_scsi(host_index)[target][cmd->lun] = ld(host_index)[ldn].device_type;
	    /* increase assignment counters for statistics in /proc */
	    IBM_DS(host_index).dynamical_assignments++;
	    IBM_DS(host_index).ldn_assignments[ldn]++;
	 } else
	   /* panic here, because a device, found at boottime has
	      vanished */
	   panic("IBM MCA SCSI: ldn=0x%x, SCSI-device on (%d,%d) vanished!\n",
		 ldn, target, cmd->lun);
	 /* unassign again all ldns (pun,lun,ldn does not matter for remove) */
	 immediate_assign(host_index,0,0,0,REMOVE_LDN);
	 /* remap all ldns, as written in the pun/lun table */
	 lun=0;
#ifdef CONFIG_SCSI_MULTI_LUN
	 for (lun=0; lun<8; lun++)
#endif
	   for (id=0; id<max_pun; id ++) {
	      if (get_ldn(host_index)[id][lun] <= MAX_LOG_DEV)
		immediate_assign(host_index,id,lun,
				 get_ldn(host_index)[id][lun],SET_LDN);
	   }
	 /* set back to normal interrupt_handling */
	 local_checking_phase_flag(host_index) = 0;
#ifdef IM_DEBUG_PROBE
	 /* Information on syslog terminal */
	 printk("IBM MCA SCSI: ldn=0x%x dynamically reassigned to (%d,%d).\n",
		ldn, target, cmd->lun);
#endif
	 /* increase next_ldn for next dynamical assignment */
	 next_ldn(host_index)++;
	 if (next_ldn(host_index)>=MAX_LOG_DEV)
	   next_ldn(host_index) = 7;
      } else {  /* wall against Linux accesses to the subsystem adapter */
	 cmd->result = DID_BAD_TARGET << 16;
	 if (done) done (cmd);
	 return 0;
      }
   }

   /*verify there is no command already in progress for this log dev */
   if (ld(host_index)[ldn].cmd)
     panic ("IBM MCA SCSI: cmd already in progress for this ldn.\n");

   /*save done in cmd, and save cmd for the interrupt handler */
   cmd->scsi_done = done;
   ld(host_index)[ldn].cmd = cmd;

   /*fill scb information independent of the scsi command */
   scb = &(ld(host_index)[ldn].scb);
   ld(host_index)[ldn].tsb.dev_status = 0;
   scb->enable = IM_REPORT_TSB_ONLY_ON_ERROR | IM_RETRY_ENABLE;
   scb->tsb_adr = virt_to_bus(&(ld(host_index)[ldn].tsb));
   scsi_cmd = cmd->cmnd[0];

   if (cmd->use_sg) {
      i = cmd->use_sg;
      sl = (struct scatterlist *)(cmd->request_buffer);
      if (i > 16)
	panic ("IBM MCA SCSI: scatter-gather list too long.\n");
      while (--i >= 0) {
	 ld(host_index)[ldn].sge[i].address = (void *)(virt_to_bus(sl[i].address));
	 ld(host_index)[ldn].sge[i].byte_length = sl[i].length;
      }
      scb->enable |= IM_POINTER_TO_LIST;
      scb->sys_buf_adr = virt_to_bus(&(ld(host_index)[ldn].sge[0]));
      scb->sys_buf_length = cmd->use_sg * sizeof (struct im_sge);
   } else {
      scb->sys_buf_adr = virt_to_bus(cmd->request_buffer);
      /* recent Linux midlevel SCSI places 1024 byte for inquiry
       * command. Far too much for old PS/2 hardware. */
      switch (scsi_cmd) {
	 /* avoid command errors by setting bufferlengths to
	  * ANSI-standard. Beware of forcing it to 255,
	  * this could SEGV the kernel!!! */
       case INQUIRY:
       case REQUEST_SENSE:
       case MODE_SENSE:
       case MODE_SELECT:
	 if (cmd->request_bufflen > 255) scb->sys_buf_length = 255;
	 else scb->sys_buf_length = cmd->request_bufflen;
	 break;
       case TEST_UNIT_READY:
	 scb->sys_buf_length = 0;
	 break;
       default:
	 scb->sys_buf_length = cmd->request_bufflen;
	 break;
      }
   }
   /*fill scb information dependent on scsi command */

#ifdef IM_DEBUG_CMD
   printk("issue scsi cmd=%02x to ldn=%d\n", scsi_cmd, ldn);
#endif

   /* for specific device-type debugging: */
#ifdef IM_DEBUG_CMD_SPEC_DEV
   if (ld(host_index)[ldn].device_type==IM_DEBUG_CMD_DEVICE)
     printk("(SCSI-device-type=0x%x) issue scsi cmd=%02x to ldn=%d\n",
	    ld(host_index)[ldn].device_type, scsi_cmd, ldn);
#endif

   /* for possible panics store current command */
   last_scsi_command(host_index)[ldn] = scsi_cmd;
   last_scsi_type(host_index)[ldn] = IM_SCB;
   /* update statistical info */
   IBM_DS(host_index).total_accesses++;
   IBM_DS(host_index).ldn_access[ldn]++;

   switch (scsi_cmd) {
    case READ_6:
    case WRITE_6:
    case READ_10:
    case WRITE_10:
    case READ_12:
    case WRITE_12:
      /* Distinguish between disk and other devices. Only disks (that are the
	 most frequently accessed devices) should be supported by the
       IBM-SCSI-Subsystem commands. */
      switch (ld(host_index)[ldn].device_type) {
       case TYPE_DISK: /* for harddisks enter here ... */
       case TYPE_MOD:  /* ... try it also for MO-drives (send flames as */
	 /*     you like, if this won't work.) */
	 if (scsi_cmd == READ_6 || scsi_cmd == READ_10 || scsi_cmd == READ_12) {
	    /* read command preparations */
	    scb->enable |= IM_READ_CONTROL;
	    IBM_DS(host_index).ldn_read_access[ldn]++; /* increase READ-access on ldn stat. */
	    scb->command = IM_READ_DATA_CMD | IM_NO_DISCONNECT;
	 } else { /* write command preparations */
	    IBM_DS(host_index).ldn_write_access[ldn]++; /* increase write-count on ldn stat.*/
	    scb->command = IM_WRITE_DATA_CMD | IM_NO_DISCONNECT;
	 }
	 if (scsi_cmd == READ_6 || scsi_cmd == WRITE_6) {
	    scb->u1.log_blk_adr = (((unsigned) cmd->cmnd[3]) << 0) |
	      (((unsigned) cmd->cmnd[2]) << 8) |
	      ((((unsigned) cmd->cmnd[1]) & 0x1f) << 16);
	    scb->u2.blk.count = (unsigned) cmd->cmnd[4];
	 } else {
	    scb->u1.log_blk_adr = (((unsigned) cmd->cmnd[5]) << 0) |
	      (((unsigned) cmd->cmnd[4]) << 8) |
	      (((unsigned) cmd->cmnd[3]) << 16) |
	      (((unsigned) cmd->cmnd[2]) << 24);
	    scb->u2.blk.count = (((unsigned) cmd->cmnd[8]) << 0) |
	      (((unsigned) cmd->cmnd[7]) << 8);
	 }
	 last_scsi_logical_block(host_index)[ldn] = scb->u1.log_blk_adr;
	 last_scsi_blockcount(host_index)[ldn] = scb->u2.blk.count;
	 scb->u2.blk.length = ld(host_index)[ldn].block_length;
	 break;
	 /* for other devices, enter here. Other types are not known by
	    Linux! TYPE_NO_LUN is forbidden as valid device. */
       case TYPE_ROM:
       case TYPE_TAPE:
       case TYPE_PROCESSOR:
       case TYPE_WORM:
       case TYPE_SCANNER:
       case TYPE_MEDIUM_CHANGER:
	 /* If there is a sequential-device, IBM recommends to use
	  IM_OTHER_SCSI_CMD_CMD instead of subsystem READ/WRITE.
	  This includes CD-ROM devices, too, due to the partial sequential
	  read capabilities. */
	 scb->command = IM_OTHER_SCSI_CMD_CMD;
	 if (scsi_cmd == READ_6 || scsi_cmd == READ_10 || scsi_cmd == READ_12)
	   /* enable READ */
	   scb->enable |= IM_READ_CONTROL;
	 scb->enable |= IM_BYPASS_BUFFER;
	 scb->u1.scsi_cmd_length = cmd->cmd_len;
	 memcpy (scb->u2.scsi_command, cmd->cmnd, cmd->cmd_len);
	 last_scsi_type(host_index)[ldn] = IM_LONG_SCB;
	 /* Read/write on this non-disk devices is also displayworthy,
	    so flash-up the LED/display. */
	 break;
      }
      break;
    case INQUIRY:
      IBM_DS(host_index).ldn_inquiry_access[ldn]++;
      scb->command = IM_DEVICE_INQUIRY_CMD;
      scb->enable |= IM_READ_CONTROL | IM_SUPRESS_EXCEPTION_SHORT | IM_BYPASS_BUFFER;
      scb->u1.log_blk_adr = 0;
      break;
    case TEST_UNIT_READY:
      scb->command = IM_OTHER_SCSI_CMD_CMD;
      scb->enable |= IM_READ_CONTROL | IM_SUPRESS_EXCEPTION_SHORT | IM_BYPASS_BUFFER;
      scb->u1.log_blk_adr = 0;
      scb->u1.scsi_cmd_length = 6;
      memcpy (scb->u2.scsi_command, cmd->cmnd, 6);
      last_scsi_type(host_index)[ldn] = IM_LONG_SCB;
      break;
    case READ_CAPACITY:
      /* the length of system memory buffer must be exactly 8 bytes */
      scb->command = IM_READ_CAPACITY_CMD;
      scb->enable |= IM_READ_CONTROL | IM_BYPASS_BUFFER;
      if (scb->sys_buf_length > 8) scb->sys_buf_length = 8;
      break;
      /* Commands that need read-only-mode (system <- device): */
    case REQUEST_SENSE:
      scb->command = IM_REQUEST_SENSE_CMD;
      scb->enable |= IM_READ_CONTROL | IM_SUPRESS_EXCEPTION_SHORT | IM_BYPASS_BUFFER;
      break;
      /* Commands that need write-only-mode (system -> device): */
    case MODE_SELECT:
    case MODE_SELECT_10:
      IBM_DS(host_index).ldn_modeselect_access[ldn]++;
      scb->command = IM_OTHER_SCSI_CMD_CMD;
      scb->enable |= IM_SUPRESS_EXCEPTION_SHORT | IM_BYPASS_BUFFER; /*Select needs WRITE-enabled*/
      scb->u1.scsi_cmd_length = cmd->cmd_len;
      memcpy (scb->u2.scsi_command, cmd->cmnd, cmd->cmd_len);
      last_scsi_type(host_index)[ldn] = IM_LONG_SCB;
      break;
      /* For other commands, read-only is useful. Most other commands are
       running without an input-data-block. */
    default:
      scb->command = IM_OTHER_SCSI_CMD_CMD;
      scb->enable |= IM_READ_CONTROL | IM_SUPRESS_EXCEPTION_SHORT | IM_BYPASS_BUFFER;
      scb->u1.scsi_cmd_length = cmd->cmd_len;
      memcpy (scb->u2.scsi_command, cmd->cmnd, cmd->cmd_len);
      last_scsi_type(host_index)[ldn] = IM_LONG_SCB;
      break;
   }
   /*issue scb command, and return */
   if (++disk_rw_in_progress == 1)
     PS2_DISK_LED_ON (shpnt->host_no, target);

   if (last_scsi_type(host_index)[ldn] == IM_LONG_SCB) {
      issue_cmd (host_index, virt_to_bus(scb), IM_LONG_SCB | ldn);
      IBM_DS(host_index).long_scbs++;
   } else {
      issue_cmd (host_index, virt_to_bus(scb), IM_SCB | ldn);
      IBM_DS(host_index).scbs++;
   }
   return 0;
}

int ibmmca_abort (Scsi_Cmnd * cmd)
{
   /* Abort does not work, as the adapter never generates an interrupt on
    * whatever situation is simulated, even when really pending commands
    * are running on the adapters' hardware ! */

   struct Scsi_Host *shpnt;
   unsigned int ldn;
   void (*saved_done) (Scsi_Cmnd *);
   int target;
   int host_index;
   int max_pun;
   static unsigned long flags;
   unsigned long imm_command;

#ifdef IM_DEBUG_PROBE
   printk("IBM MCA SCSI: Abort subroutine called...\n");
#endif
   IBMLOCK
   shpnt = cmd->host;
   /* search for the right hostadapter */
   for (host_index = 0; hosts[host_index] && hosts[host_index]->host_no != shpnt->host_no; host_index++);

   if (!hosts[host_index]) { /* invalid hostadapter descriptor address */
      cmd->result = DID_NO_CONNECT << 16;
      if (cmd->scsi_done) (cmd->scsi_done) (cmd);
      shpnt = cmd->host;
      IBMUNLOCK
#ifdef IM_DEBUG_PROBE
      printk("IBM MCA SCSI: Abort adapter selection failed!\n");
#endif
      return SCSI_ABORT_SNOOZE;
   }
   max_pun = subsystem_maxid(host_index);
   if (ibm_ansi_order) {
      target = max_pun - 1 - cmd->target;
      if ((target <= subsystem_pun(host_index))&&(cmd->target <= subsystem_pun(host_index)))
	target--;
      else if ((target >= subsystem_pun(host_index))&&(cmd->target >= subsystem_pun(host_index)))
	target++;
   } else
     target = cmd->target;

   /* get logical device number, and disable system interrupts */
   printk ("IBM MCA SCSI: Sending abort to device pun=%d, lun=%d.\n",
	   target, cmd->lun);
   ldn = get_ldn(host_index)[target][cmd->lun];

   /*if cmd for this ldn has already finished, no need to abort */
   if (!ld(host_index)[ldn].cmd) {
      IBMUNLOCK
      return SCSI_ABORT_NOT_RUNNING;
   }

   /* Clear ld.cmd, save done function, install internal done,
    * send abort immediate command (this enables sys. interrupts),
    * and wait until the interrupt arrives.
    */
   saved_done = cmd->scsi_done;
   cmd->scsi_done = internal_done;
   cmd->SCp.Status = 0;
   last_scsi_command(host_index)[ldn] = IM_ABORT_IMM_CMD;
   last_scsi_type(host_index)[ldn] = IM_IMM_CMD;
   imm_command = inl(IM_CMD_REG(host_index));
   imm_command &= (unsigned long)(0xffff0000); /* mask reserved stuff */
   imm_command |= (unsigned long)(IM_ABORT_IMM_CMD);
   /* must wait for attention reg not busy */
   while (1) {
      if (!(inb (IM_STAT_REG(host_index)) & IM_BUSY))
	break;
      IBMUNLOCK
      IBMLOCK
   }
   /* write registers and enable system interrupts */
   outl (imm_command, IM_CMD_REG(host_index));
   outb (IM_IMM_CMD | ldn, IM_ATTN_REG(host_index));
   IBMUNLOCK
#ifdef IM_DEBUG_PROBE
   printk("IBM MCA SCSI: Abort queued to adapter...\n");
#endif
   while (!cmd->SCp.Status) barrier ();
   cmd->scsi_done = saved_done;
#ifdef IM_DEBUG_PROBE
   printk("IBM MCA SCSI: Abort returned with adapter response...\n");
#endif

   /*if abort went well, call saved done, then return success or error */
   if (cmd->result == (DID_ABORT << 16)) {
      IBMLOCK
      cmd->result |= DID_ABORT << 16;
      if (cmd->scsi_done) (cmd->scsi_done) (cmd);
      ld(host_index)[ldn].cmd = NULL;
      IBMUNLOCK
#ifdef IM_DEBUG_PROBE
      printk("IBM MCA SCSI: Abort finished with success.\n");
#endif
      return SCSI_ABORT_SUCCESS;
   } else {
      IBMLOCK
      cmd->result |= DID_NO_CONNECT << 16;
      if (cmd->scsi_done) (cmd->scsi_done) (cmd);
      ld(host_index)[ldn].cmd = NULL;
      IBMUNLOCK
#ifdef IM_DEBUG_PROBE
      printk("IBM MCA SCSI: Abort failed.\n");
#endif
      return SCSI_ABORT_ERROR;
   }
}

int ibmmca_reset (Scsi_Cmnd * cmd, unsigned int reset_flags)
{
   struct Scsi_Host *shpnt;
   Scsi_Cmnd *cmd_aid;
   int ticks,i;
   int host_index;
   static unsigned long flags;
   unsigned long imm_command;

   if (cmd == NULL) {
      printk("IBM MCA SCSI: Reset called with NULL-command!\n");
      return(SCSI_RESET_SNOOZE);
   }
   IBMLOCK
   ticks = IM_RESET_DELAY*HZ;
   shpnt = cmd->host;
   /* search for the right hostadapter */
   for (host_index = 0; hosts[host_index] && hosts[host_index]->host_no != shpnt->host_no; host_index++);

   if (!hosts[host_index]) /* invalid hostadapter descriptor address */
     return SCSI_ABORT_SNOOZE;

   if (local_checking_phase_flag(host_index)) {
      printk("IBM MCA SCSI: unable to reset while checking devices.\n");
      IBMUNLOCK
      return SCSI_RESET_SNOOZE;
   }

   /* issue reset immediate command to subsystem, and wait for interrupt */
   printk("IBM MCA SCSI: resetting all devices.\n");
   reset_status(host_index) = IM_RESET_IN_PROGRESS;
   last_scsi_command(host_index)[0xf] = IM_RESET_IMM_CMD;
   last_scsi_type(host_index)[0xf] = IM_IMM_CMD;
   imm_command = inl(IM_CMD_REG(host_index));
   imm_command &= (unsigned long)(0xffff0000); /* mask reserved stuff */
   imm_command |= (unsigned long)(IM_RESET_IMM_CMD);
   /* must wait for attention reg not busy */
   while (1) {
      if (!(inb (IM_STAT_REG(host_index)) & IM_BUSY))
	break;
      IBMUNLOCK
      IBMLOCK
   }
   /*write registers and enable system interrupts */
   outl (imm_command, IM_CMD_REG(host_index));
   outb (IM_IMM_CMD | 0xf, IM_ATTN_REG(host_index));
   /* wait for interrupt finished or intr_stat register to be set, as the
    * interrupt will not be executed, while we are in here! */
   while (reset_status(host_index) == IM_RESET_IN_PROGRESS && --ticks
	  && ((inb(IM_INTR_REG(host_index)) & 0x8f)!=0x8f)) {
      udelay((1+999/HZ)*1000);
      barrier();
   }
   /* if reset did not complete, just return an error*/
   if (!ticks) {
      printk("IBM MCA SCSI: reset did not complete within %d seconds.\n",
	     IM_RESET_DELAY);
      reset_status(host_index) = IM_RESET_FINISHED_FAIL;
      IBMUNLOCK
      return SCSI_RESET_ERROR;
   }

   if ((inb(IM_INTR_REG(host_index)) & 0x8f)==0x8f) {
      /* analysis done by this routine and not by the intr-routine */
      if (inb(IM_INTR_REG(host_index))==0xaf)
	reset_status(host_index) = IM_RESET_FINISHED_OK_NO_INT;
      else if (inb(IM_INTR_REG(host_index))==0xcf)
	reset_status(host_index) = IM_RESET_FINISHED_FAIL;
      else /* failed, 4get it */
	reset_status(host_index) = IM_RESET_NOT_IN_PROGRESS_NO_INT;
      outb (IM_EOI | 0xf, IM_ATTN_REG(host_index));
   }

   /* if reset failed, just return an error */
   if (reset_status(host_index) == IM_RESET_FINISHED_FAIL) {
      printk("IBM MCA SCSI: reset failed.\n");
      IBMUNLOCK
      return SCSI_RESET_ERROR;
   }

   /* so reset finished ok - call outstanding done's, and return success */
   printk ("IBM MCA SCSI: Reset successfully completed.\n");
   IBMUNLOCK
   for (i = 0; i < MAX_LOG_DEV; i++) {
      cmd_aid = ld(host_index)[i].cmd;
      if (cmd_aid && cmd_aid->scsi_done) {
	 ld(host_index)[i].cmd = NULL;
	 cmd_aid->result = DID_RESET << 16;
      }
   }
   if (reset_flags & SCSI_RESET_SUGGEST_HOST_RESET)
     return (SCSI_RESET_SUCCESS | SCSI_RESET_HOST_RESET);
   else if (reset_flags & SCSI_RESET_SUGGEST_BUS_RESET)
     return (SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET);
   else
     return SCSI_RESET_SUCCESS;
}

int ibmmca_biosparam (Disk * disk, kdev_t dev, int *info)
{
   info[0] = 64;
   info[1] = 32;
   info[2] = disk->capacity / (info[0] * info[1]);
   if (info[2] >= 1024) {
      info[0] = 128;
      info[1] = 63;
      info[2] = disk->capacity / (info[0] * info[1]);
      if (info[2] >= 1024) {
	 info[0] = 255;
	 info[1] = 63;
	 info[2] = disk->capacity / (info[0] * info[1]);
	 if (info[2] >= 1024)
	   info[2] = 1023;
      }
   }
   return 0;
}

/* calculate percentage of total accesses on a ldn */
static int ldn_access_load(int host_index, int ldn)
{
   if (IBM_DS(host_index).total_accesses == 0) return (0);
   if (IBM_DS(host_index).ldn_access[ldn] == 0) return (0);
   return (IBM_DS(host_index).ldn_access[ldn] * 100) / IBM_DS(host_index).total_accesses;
}

/* calculate total amount of r/w-accesses */
static int ldn_access_total_read_write(int host_index)
{
   int a;
   int i;

   a = 0;
   for (i=0; i<=MAX_LOG_DEV; i++)
     a+=IBM_DS(host_index).ldn_read_access[i]+IBM_DS(host_index).ldn_write_access[i];
   return(a);
}

static int ldn_access_total_inquiry(int host_index)
{
   int a;
   int i;

   a = 0;
   for (i=0; i<=MAX_LOG_DEV; i++)
     a+=IBM_DS(host_index).ldn_inquiry_access[i];
   return(a);
}

static int ldn_access_total_modeselect(int host_index)
{
   int a;
   int i;

   a = 0;
   for (i=0; i<=MAX_LOG_DEV; i++)
     a+=IBM_DS(host_index).ldn_modeselect_access[i];
   return(a);
}

/* routine to display info in the proc-fs-structure (a deluxe feature) */
int ibmmca_proc_info (char *buffer, char **start, off_t offset, int length,
		      int hostno, int inout)
{
   int len=0;
   int i,id,lun,host_index;
   struct Scsi_Host *shpnt;
   unsigned long flags;
   int max_pun;

   IBMLOCK
   for (i = 0; hosts[i] && hosts[i]->host_no != hostno; i++);
   shpnt = hosts[i];
   host_index = i;
   if (!shpnt) {
      len += sprintf(buffer+len, "\nIBM MCA SCSI: Can't find adapter for host number %d\n", hostno);
      return len;
   }
   max_pun = subsystem_maxid(host_index);

   len += sprintf(buffer+len, "\n             IBM-SCSI-Subsystem-Linux-Driver, Version %s\n\n\n",
		  IBMMCA_SCSI_DRIVER_VERSION);
   len += sprintf(buffer+len, " SCSI Access-Statistics:\n");
   len += sprintf(buffer+len, "               Device Scanning Order....: %s\n",
		  (ibm_ansi_order) ? "IBM/ANSI" : "New Industry Standard");
#ifdef CONFIG_SCSI_MULTI_LUN
   len += sprintf(buffer+len, "               Multiple LUN probing.....: Yes\n");
#else
   len += sprintf(buffer+len, "               Multiple LUN probing.....: No\n");
#endif
   len += sprintf(buffer+len, "               This Hostnumber..........: %d\n",
		  hostno);
   len += sprintf(buffer+len, "               Base I/O-Port............: 0x%x\n",
		  (unsigned int)(IM_CMD_REG(host_index)));
   len += sprintf(buffer+len, "               (Shared) IRQ.............: %d\n",
		  IM_IRQ);
   len += sprintf(buffer+len, "               Total Interrupts.........: %d\n",
		  IBM_DS(host_index).total_interrupts);
   len += sprintf(buffer+len, "               Total SCSI Accesses......: %d\n",
		  IBM_DS(host_index).total_accesses);
   len += sprintf(buffer+len, "               Total short SCBs.........: %d\n",
		  IBM_DS(host_index).scbs);
   len += sprintf(buffer+len, "               Total long SCBs..........: %d\n",
		  IBM_DS(host_index).long_scbs);
   len += sprintf(buffer+len, "                 Total SCSI READ/WRITE..: %d\n",
		  ldn_access_total_read_write(host_index));
   len += sprintf(buffer+len, "                 Total SCSI Inquiries...: %d\n",
		  ldn_access_total_inquiry(host_index));
   len += sprintf(buffer+len, "                 Total SCSI Modeselects.: %d\n",
		  ldn_access_total_modeselect(host_index));
   len += sprintf(buffer+len, "                 Total SCSI other cmds..: %d\n",
		  IBM_DS(host_index).total_accesses - ldn_access_total_read_write(host_index)
		  - ldn_access_total_modeselect(host_index)
		  - ldn_access_total_inquiry(host_index));
   len += sprintf(buffer+len, "               Total SCSI command fails.: %d\n\n",
		  IBM_DS(host_index).total_errors);
   len += sprintf(buffer+len, " Logical-Device-Number (LDN) Access-Statistics:\n");
   len += sprintf(buffer+len, "         LDN | Accesses [%%] |   READ    |   WRITE   | ASSIGNMENTS\n");
   len += sprintf(buffer+len, "        -----|--------------|-----------|-----------|--------------\n");
   for (i=0; i<=MAX_LOG_DEV; i++)
     len += sprintf(buffer+len, "         %2X  |    %3d       |  %8d |  %8d | %8d\n",
		    i, ldn_access_load(host_index, i), IBM_DS(host_index).ldn_read_access[i],
		    IBM_DS(host_index).ldn_write_access[i], IBM_DS(host_index).ldn_assignments[i]);
   len += sprintf(buffer+len, "        -----------------------------------------------------------\n\n");
   len += sprintf(buffer+len, " Dynamical-LDN-Assignment-Statistics:\n");
   len += sprintf(buffer+len, "               Number of physical SCSI-devices..: %d (+ Adapter)\n",
		  IBM_DS(host_index).total_scsi_devices);
   len += sprintf(buffer+len, "               Dynamical Assignment necessary...: %s\n",
		  IBM_DS(host_index).dyn_flag ? "Yes" : "No ");
   len += sprintf(buffer+len, "               Next LDN to be assigned..........: 0x%x\n",
		  next_ldn(host_index));
   len += sprintf(buffer+len, "               Dynamical assignments done yet...: %d\n",
		  IBM_DS(host_index).dynamical_assignments);
   len += sprintf(buffer+len, "\n Current SCSI-Device-Mapping:\n");
   len += sprintf(buffer+len, "        Physical SCSI-Device Map               Logical SCSI-Device Map\n");
   len += sprintf(buffer+len, "    ID\\LUN  0  1  2  3  4  5  6  7       ID\\LUN  0  1  2  3  4  5  6  7\n");
   for (id=0; id<max_pun; id++) {
      len += sprintf(buffer+len, "    %2d     ",id);
      for (lun=0; lun<8; lun++)
	len += sprintf(buffer+len,"%2s ",ti_p(get_scsi(host_index)[id][lun]));
      len += sprintf(buffer+len, "      %2d     ",id);
      for (lun=0; lun<8; lun++)
	len += sprintf(buffer+len,"%2s ",ti_l(get_ldn(host_index)[id][lun]));
      len += sprintf(buffer+len,"\n");
   }

   len += sprintf(buffer+len, "(A = IBM-Subsystem, D = Harddisk, T = Tapedrive, P = Processor, W = WORM,\n");
   len += sprintf(buffer+len, " R = CD-ROM, S = Scanner, M = MO-Drive, C = Medium-Changer, + = unprovided LUN,\n");
   len += sprintf(buffer+len, " - = nothing found, nothing assigned or unprobed LUN)\n\n");

   *start = buffer + offset;
   len -= offset;
   if (len > length) len = length;
   IBMUNLOCK
   return len;
}

void ibmmca_scsi_setup (char *str, int *ints)
{
   internal_ibmmca_scsi_setup (str, ints);
}

static int option_setup(char *str)
{
   int ints[IM_MAX_HOSTS];
   char *cur = str;
   int i = 1;

   while (cur && isdigit(*cur) && i <= IM_MAX_HOSTS) {
      ints[i++] = simple_strtoul(cur, NULL, 0);
      if ((cur = strchr(cur,',')) != NULL) cur++;
   }
   ints[0] = i - 1;
   internal_ibmmca_scsi_setup(cur, ints);
   return 0;
}

__setup("ibmmcascsi=", option_setup);

#ifdef MODULE
/* Eventually this will go into an include file, but this will be later */
Scsi_Host_Template driver_template = IBMMCA;

#include "scsi_module.c"
#endif
